Twilight

Question #1: Why then?

“After sunset on a Friday evening, may I ask a non-Jewish person to turn on the lights?”

Question #2: Until when?

“May I toivel dishes, glasses and silverware during the same twilight period?”

Question #3: Challah

“May I separate challah during bein hashemashos?”

Introduction: Twilight laws

As we are all aware, the halachic day begins and ends at nightfall. But at what exact moment does one day march off into history and its successor arrive with its banner unfurled? Is it before sunset, at sunset, when the stars appear, or dependent on some other factor? And, if a day begins when the stars appear, which stars and how many? Does the amount of time after sunset vary according to longitude and/or season of the year? And does it, perhaps, vary according to the amount of humidity in the atmosphere?

There is much discussion in the Gemara and the poskim concerning many of these issues, some of which I have written about previously. This article will discuss the halachic rules that apply during the period of time called bein hashemashos, which is the term used to refer to the twilight interval when we are uncertain whether it is still day or already night. Of particular concern is what is the halacha of this time on Friday evening, when it is unclear whether or not Shabbos has already begun. Does bein hashemashos have the exact same halachic status as the time that is definitely Shabbos, or does its questionable status allow any lenience? The answer is that, under extenuating circumstances, some lenience is allowed. We will see that the definition of “extenuating” for these purposes is rather moderate.

The earliest sources

In several places, the Mishnah, the Gemara and the poskim explain that certain activities that are prohibited on Shabbos are permitted during bein hashemashos of Friday evening. We will begin our research with a Mishnah (Shabbos 34a) that many recite every Friday evening in shul, as the last passage in Bameh Madlikin. There, it teaches: If it is in doubt whether nightfall has already arrived, it is forbidden to separate maaser from produce, when we are certain that it was not yet separated. (Such untithed produce is referred to as tevel.) It is also prohibited to immerse vessels to make them tahor. (Unfortunately, since we are all tamei today, this question is not relevant, but we will soon discuss whether immersing vessels used for food that were previously owned by a non-Jew is permitted during bein hashemashos.) The Mishnah also prohibits kindling lights during bein hashemashos. However, it permits separating maaser from demai produce, about which it is uncertain whether this separation is required. It is permitted during bein hashemashos to make an eiruv chatzeiros, which allows carrying from one’s house to a neighbor’s house on Shabbos. The Mishnah also permits insulating food, hatmanah, using something that does not increase heat (such as clothing), notwithstanding that this is prohibited on Shabbos.

As we will see shortly, there is much discussion among rishonim and early poskim whether we rule according to the conclusions of this Mishnah, or whether we rule more leniently. But first, we need to understand each of the halachic issues that the Mishnah mentions. For example, what is wrong with separating maasros, even on Shabbos itself? Which melacha of Shabbos does this violate?

Maasering

The Mishnah (Beitzah 36b) prohibits separating maasros on Yom Tov, and certainly on Shabbos. The reason for this prohibition is that, since it makes the food edible halachically, it is viewed as a form of forbidden “repair work.”

Demai has an in-between status. What is demai? In the times of Chazal, observant but poorly educated Jews observed the mitzvos, although some of them would occasionally “cut corners,” violating details of halachos that involve major expense. These people, called amei ha’aretz, were lax predominantly regarding three areas of halacha –the laws of shemittah, the laws of tumah and taharah, and the laws of separating maasros. Although most amei ha’aretz indeed separated maasros faithfully, Chazal instituted that produce purchased from an am ha’aratz should have maaser separated from it, albeit without first reciting the brocha for taking maaser. This produce was called demai, and the institution of this takkanah was because it was difficult to ascertain which amei ha’aretz were separating maasros and which were not. Thus, we treat this produce as a type of safek tevel. For this reason, the brocha for separating maasros was omitted prior to separating maaser from demai because, indeed, most amei ha’aretz separated maasros. In addition, because most amei ha’aretz separated maasros, Chazal allowed other leniencies pertaining to its use; for example, they permitted serving demai produce to the poor or to soldiers in the army.

Because there is a great deal of reason to be lenient relative to demai, the Mishnah permitted separating maasros from it during bein hashemashos (Shabbos 34a). The reason this is permitted is because this separation may not actually be “fixing” anything – it is more than likely that the maasros were already separated.

Immersing utensils

During bein hashemashos, the Mishnah permitted immersing vessels and other items that had previously become tamei. This immersion is prohibited on Shabbos or Yom Tov, itself, as mentioned in Mesechta Beitzah (Mishnah 17b and Gemara ad loc.). There, the Gemara (Beitzah 18a) cites a four-way dispute why it is prohibited to immerse vessels to make them tahor on Shabbos or Yom Tov. The four reasons are:

1. Someone immersing vessels on Shabbos may inadvertently carry them through a public area. According to this opinion, immersing vessels on Yom Tov was prohibited as an extension of the prohibition of Shabbos.

2. Clothing and cloth that became tamei, and was then toiveled on Shabbos or Yom Tov, could cause someone to squeeze out the water. According to this opinion, immersing pots, plates, silverware and other items that do not absorb water was prohibited as an extension of the prohibition to immerse cloth and other squeezable items.

3. Knowing that someone has time to toivel vessels on Shabbos or Yom Tov, the owner might delay toiveling them until then. This procrastination might then result in foods or other vessels becoming tamei. Banning the immersions on Shabbos or Yom Tov would cause people to immerse the vessels at an earlier opportunity.

4. Immersing vessels to make them usable is considered “repairing” them on Shabbos or Yom Tov.

The rishonim disagree how we rule in this dispute: in other words, which of the four reasons is accepted (see Rif, Rosh, etc.). There are halachic ramifications of this dispute. Although immersing vessels to make them tahor is not a germane topic today, since we are all tamei anyway, the question is raised whether vessels acquired from a non-Jew, which require immersion in a mikveh prior to use, may be immersed on Shabbos and Yom Tov. When we look at the reasons mentioned by the Gemara why Chazal forbade immersing tamei vessels on Shabbos and Yom Tov, we can conclude that some of the reasons should definitely apply to the immersing of vessels for this latter reason, whereas others might not. The Rosh concludes that it is prohibited on Shabbos and Yom Tov to immerse vessels acquired from a non-Jew. (See, however, Shaagas Aryeh #56.) We will discuss shortly whether one can immerse them during bein hashemashos.

Kindling lights

During bein hashemashos, any Torah prohibition cannot be performed because of safek de’oraysa lechumrah, the rule that cases of doubt regarding Torah prohibitions are treated stringently. The Mishnah’s example of this is kindling lights, which is certainly forbidden during bein hashemashos.

Hatmanah — Insulating food

The Gemara explains that the Mishnah’s last ruling, insulating food, is permitted bein hashemashos because of a specific reason applicable only to its case. Since explaining the details of this rabbinic injunction, called hatmanah, would take us far afield, we will forgo that discussion in this article.

Rebbe and the Rabbanan

Up until this point, I have been explaining the Mishnah in Bameh Madlikin. However, elsewhere, the Gemara (Eruvin 32b) cites a dispute between Rebbe and the Rabbanan, in which Rebbe contends that all rabbinic prohibitions may be performed during the bein hashemashos period, whereas the Rabbanan prohibit this. The obvious reading of the Mishnah in Bameh Madlikin is that it follows the approach of the Rabbanan who prohibit performing most rabbinically prohibited acts during the bein hashemashos period, and, indeed, this is how Rashi explains that Mishnah. However, the Gemara (Eruvin 32b-34b) demonstrates that the Mishnah there in Eruvin follows the opinion of Rebbe. On its own, this is not a halachic concern, since there are instances in which different Mishnayos follow the opinions of different tana’im. The practical question that needs to be decided is whether we indeed rule according to the Rabbanan’s position as stated in the Mishnah in Bameh Madlikin, or whether we follow Rebbe’s more lenient ruling. The conclusion of the Gemara in Eruvin implies that the halacha follows the opinion of Rebbe, and not that of the Rabbanan.

Among the rishonim, we find variant halachic conclusions regarding this question (Rashi, Shabbos 34a s.v. safek; Rambam, Hilchos Shabbos 24:10 and Hilchos Eruvin 6:9; Tur Orach Chayim 342; Beis Yosef Orach Chayim 261 and 342). The Shulchan Aruch (Orach Chayim 342) concludes according to the Rambam’s opinion, ruling that during bein hashemashos Chazal did not forbid anything that is prohibited because of a rabbinic injunction, provided that there is some mitzvah involved or that there were extenuating reasons why it was not performed on erev Shabbos. The Shulchan Aruch mentions, specifically, that it is permitted during bein hashemashos to climb a tree on Rosh Hashanah to get a shofar in order to perform the mitzvah, although it is prohibited to climb a tree on Yom Tov itself even if, as a result, you will be unable to blow shofar. Returning to our first question (“After sunset on a Friday evening, may I ask a non-Jewish person to turn on the lights?”, the Shulchan Aruch also permits asking a non-Jew to kindle a light during bein hashemashos. The Mishnah Berurah 261:17 permits asking him, even if you already accepted Shabbos.

Similarly, the Magen Avraham (261:6) permits separating maasros during bein hashemashos, if you do not have enough food ready for Shabbos. (The Ketzos Hashulchan [75:5, 6 in Badei Hashulchan] explains that the situation is such that he does not have enough fruit or vegetables to have an enjoyable Shabbos meal.) It is very interesting that the Magen Avraham permits this, because the Mishnah at the end of Bameh Madlikin thatwe quoted above expressly prohibits separating maasros during bein hashemashos. Nevertheless, the Magen Avraham permits this separating of maasros, since we rule according to Rebbe, not like the Mishnah.

Toiveling during bein hashemashos

With this background, let us examine the second of our opening questions: is it permitted during the bein hashemashos period to toivel dishes, glasses and silverware purchased from a non-Jew? Assuming we conclude, like the Rosh does, that it is prohibited to toivel these items on Shabbos or Yom Tov, which is the common practice, someone who has no others to use on Shabbos or Yom Tov may toivel them during bein hashemashos (Magen Avraham 261:6).

Separating challah

There is much discussion among halachic authorities whether it is permitted to separate challah during bein hashemashos, if you realize that you forgot to do so before. As we will see shortly, the Magen Avraham (261:2) prohibits separating challah bein hashemashos, whereas other authorities qualify this. To explain their halachic conclusions, we need to provide some background to the laws of separating challah.

Although people are often surprised to discover this, challah is categorized under the mitzvos ha’teluyos ba’aretz, the agricultural mitzvos that apply min haTorah only in Eretz Yisroel. The requirement of separating challah from dough made in chutz la’aretz is a rabbinic requirement. However, when implementing this requirement, Chazal instructed that the mitzvah be performed in a different way from how it is observed in Eretz Yisroel. Dough made in Eretz Yisroel that has not yet had its challah portion separated has the halachic status of tevel and may not be eaten. Dough made in chutz la’aretz does not become tevel. There is a mitzvah to separate challah, but this mitzvah can be fulfilled even after most of the dough has been eaten.

Therefore, should one realize on Shabbos that challah was not separated from dough made in Eretz Yisroel, the bread cannot be eaten because it is tevel. However, if the dough was made in chutz la’aretz, the bread can be eaten on Shabbos, and the challah separated after Shabbos. To do this, you must make sure that you keep some of the bread until after Shabbos, and then separate challah from what was set aside.

Reverse the law

The result of this halacha is that dough produced in chutz la’aretz does not require that its challah is separated in order to permit eating it on Shabbos, whereas dough produced in Eretz Yisroel does. We therefore have an anomalous conclusion regarding whether the challah may be separated during bein hashemashos. Challah may not be separated from dough made in chutz la’aretz, because you can wait to separate the challah until after Shabbos. The later authorities explain that this is the intention of the ruling of the Magen Avraham (261:2). However, when the dough was prepared in Eretz Yisroel and challah was not taken, it will be forbidden to eat the bread on Shabbos. Therefore, when you realize that you forgot to separate challah, and you are relying on that bread for your Shabbos meals, you may separate the challah during bein hashemashos (Machatzis Hashekel 261:2; Pri Megadim, Eishel Avraham 261:2; Mishnah Berurah 261:4).

We can now address the third of our opening questions: “May I separate challah during bein hashemashos?” The answer is that if the dough was mixed in chutz la’aretz, I may not, but I may eat the baked bread during Shabbos, as long as I leave some of it for after Shabbos and then separate challah retroactively. On the other hand, if the dough was made in Eretz Yisroel, I may therefore not eat it without first separating challah, and I may separate the challah during bein hashemashos.

In conclusion

The Gemara teaches that the rabbinic laws are dearer to Hashem than the Torah laws. In this instance, we see that Chazal provided lenience to permit otherwise prohibited activities to be done during the bein hashemashos period.

Rav Samson Raphael Hirsch (Shemos 20:10) notes that people mistakenly think that work is prohibited on Shabbos, in order for it to be a day of rest. He points out that the Torah does not prohibit doing avodah, which connotes hard work, but melachah, activities or actions which bring purpose and accomplishment. Shabbos is the day on which we refrain from constructing and altering the world for our own purposes. The goal of Shabbos is to allow Hashem’s rule to be the focus of creation, by refraining from our own creative acts (Shemos 20:11).




Must I Toivel This?

Photo by Thomas Picard from FreeImages

Question #1: The Vanilla Cruet

“We received a gift of a glass cruet, a salad oil dispenser,
that we doubt we will ever use for that purpose. We decided, instead, to use it
is a flower vase and were told that we do not need to toivel it.
Subsequently, we decided that we might use it for soaking vanilla beans and
alcohol to make our own natural vanilla extract. Do we need to toivel
it?”

Question #2: Restaurant Silverware

“I have always assumed that caterers and restaurants toivel
their silverware and glasses. Recently, I was told that some hechsherim
do not require this. Is this true? Am I permitted to use their silverware and
glasses?”

Question #3: The Salami Slicer

“I have a knife that I use for my work, which is not
food-related. May I occasionally slice a salami with the knife that I have
never immersed in a mikveh?”

Question #4: The Box Cutter

“Before I toivel my new steak knife, may I use it to
open a box?

Answer:

After the Bnei Yisroel’s miraculous victory over the
nation of Midyan, they were commanded regarding the booty that they had now
acquired: Concerning the gold and the silver; the copper, the iron, the tin
and the lead: any item that was used in fire needs to be placed in fire to
become pure – yet, it must also be purified in mikveh water. And that which was
not used in fire must pass through water
(Bamidbar 31:22-23). From
these verses, our Sages derive the mitzvah of tevilas keilim — the requirement
to immerse metal implements used for food in a spring or kosher mikveh
prior to use. According to the Talmud Yerushalmi (Avodah Zarah 5:15),
the immersion of the implement elevates it to the sanctity of Jewish ownership,
similar to the requirement that a non-Jew converting to Judaism submerges in a mikveh
(Issur Vaheter 58:76; see also Ritva, Avodah Zarah 75b).

The Gemara (Avodah Zarah 75b) rules that, in
addition to metal items, we are also required to immerse glass utensils,
because both metal and glass are similar: they are recyclable. When they break,
one can melt or weld the broken parts to create new utensils or to repair old
ones. As a matter of fact, in the time of the Gemara, people kept broken
pieces of metal and brought them to the blacksmith when they needed to
manufacture new items (see Shabbos 123a). It is also interesting to note
that this function is the basis of the Hebrew word for metal, mateches, which
means meltable or dissolvable (see Yechezkel 22:22; Rashi,
Shemos
9:33). In this characteristic, metal ware and glassware are
different from items made of stone, wood or earthenware, which cannot be
recycled in this manner.

Prior to dipping the metal ware or glassware, one recites a brocha,
Asher ki’deshanu bemitzvosav vetzivanu al tevilas keilim. As we will
soon see, this brocha is recited only when there is a definite
requirement to toivel (immerse) an item.

Used without immersing

If, in violation of the Law, someone used an item that was
not immersed, may one eat the food that came in contact with it? According to
many authorities, this is the subject of a dispute between two opinions in the Gemara.
Some early authorities (Baal Halachos Gedolos, Chapter 55; Or Zarua,
Piskei Avodah Zarah
#293) conclude that, indeed, this food is prohibited.
However, the consensus of halachic authority is that it is permitted to
eat food that was prepared using non-toiveled equipment (Tosafos,
Avodah Zarah
75b s.v. Vechulan; Ritva, ad locum; Rema, Yoreh Deah
120:16). This is useful information when visiting someone who,
unfortunately, does not perform the mitzvah of tevilas keilim. Although
one may not use non-toiveled utensils to eat or drink, the food prepared
in them remains kosher. According to most authorities, if the food is served in
non-toiveled utensils, one should transfer it to utensils that do not
require immersion or were properly immersed.

The halachah is that when I know that someone will use
pots and other equipment that were not immersed, I may not ask him to cook for
me, since I am causing him to violate the Torah (lifnei iveir).

A matir or a takkanah?

Why is it forbidden to use a utensil that has not been toiveled?
There are two different ways to understand this halachah.

A matir

The first approach explains that min HaTorah one may
not use a utensil that has not been immersed, similar to the halachah
that one may not eat meat without first shechting the animal. This logic
holds that when the Torah created the mitzvah of tevilas keilim, it
prohibited use of any food utensils that require immersion, and the immersion
is what permits me to use the utensils. I will refer to this approach as
holding that tevilas keilim is a matir.

A takkanah

Alternatively, one can explain that, although the
requirement to immerse food utensils is min HaTorah, the prohibition to
use non-toiveled utensils is a takkanah, a rabbinic prohibition. The
reason for this prohibition is to encourage people to immerse their utensils in
a timely fashion. Chazal were concerned that if it is permitted to use
utensils without immersing them, people would postpone, indefinitely,
fulfilling the mitzvah.

This second approach appears to be how the Mishnah
Berurah
understood this mitzvah, since he states that although most
authorities contend that the mitzvah to immerse utensils is min HaTorah,
the prohibition to use them if they were not immersed is only rabbinic (Biur
Halachah
323:7 s.v. Mutar). This exact idea is expressed by Rav
Shlomoh Zalman Auerbach (Minchas Shlomoh 2:66:13, 14).

Notwithstanding the Mishnah Berurah’s understanding
of this mitzvah, the Or Zarua,a rishon, writes that the
prohibition to use non-immersed equipment is min HaTorah (Or Zarua,
Piskei Avodah Zarah
#293; A careful reading of Shaagas Aryeh #56
will demonstrate that he was of the same opinion.) This implies that the
mitzvah is indeed a matir, its purpose is to permit the use of the utensil.
If not, where do we have any evidence that the Torah prohibited use of a
non-immersed vessel?

Rushing to immerse

Is there a halachic requirement to immerse a utensil
as soon as I purchase it, or may I wait for a convenient time to immerse it, as
long as I do not use the utensil in the interim?

We find a dispute among the poskim concerning this.
Some rule that there is no requirement to immerse a utensil as soon as possible
(Levush, as explained by Pri Megadim, Mishbetzos Zahav, Orach Chayim 323:5),whereas the Maharshal (Yam shel Shelomoh, Beitzah 2:19)
explains that this question is dependent on a dispute in the Gemara (Beitzah
17b-18a). The Maharshal concludes that one is required to immerse
the utensil as soon as possible, out of concern that one will mistakenly use it
before it was immersed. The latter ruling is quoted by other authorities (Elyah
Rabbah
323:12).

Better to borrow?

The Gemara (Avodah Zarah 75b) explains that
the mitzvah of tevilas keilim does not apply to utensils that a Jew
borrowed or rented from a non-Jew (Shulchan Aruch, Yoreh Deah 120:8).
The Torah taught that utensils that a Jew acquires require immersing,
but not items that are not owned by a Jew. Furthermore, whether a utensil
requires immersion is determined by who its owner is and not by who is using
it. We will soon see another ramification of this ruling.

The poskim rule that, under circumstances when one
cannot immerse utensils, one may transfer ownership of a utensil from a Jew to
a non-Jew to avoid immersing it. Therefore, should a Jew own a utensil and have
nowhere to immerse it, or if he does not have time before Shabbos or Yom
Tov
to immerse it, he may give it to a gentile and then borrow it back from
the gentile (Mordechai, Beitzah #677; Shulchan Aruch and Rema,
Yoreh Deah
120:16). Since the utensil is now owned by a gentile, there is
no requirement to immerse it. Consequently, borrowing it from the gentile does
not present any problem.

This ruling applies only to utensils that are owned by a
non-Jew and borrowed from him by a Jew. However, if a Jew owns a utensil that
he has not immersed, another Jew may not borrow or use it without immersing it
(Tosafos and Rosh ad loc., both quoting Rashbam). Once the
owner is required to immerse the utensil, no other Jew may use it without
immersing it first.

Only klei seudah

The Gemara concludes that the mitzvah of tevilas
keilim
applies only to klei seudah — literally, implements used for
a meal. This includes items used to prepare food or to eat. As we will soon
discuss, there are some interesting ramifications of this law.

“Rav Nachman said in the name of Rabbah bar Avuha: ‘One
can derive from the verse that one must immerse even brand-new items, because
used vessels that were purged in fire have the same kashrus status as brand
new, and yet they require immersion.’

Rav Sheishes then asked him: ‘If it is true that the mitzvah
of immersing vessels is not because of kashrus concerns, then maybe one
is required to immerse even clothing shears?’

Rav Nachman responded: ‘The Torah mentions only vessels that
are used for meals (klei seudah)'” (Avodah Zarah 75b).

Rav Sheishes suggested that if the immersion of utensils is
not a means of kashering a non-kosher vessel, then perhaps we have many
more opportunities to fulfill this mitzvah, and it applies to any type of
paraphernalia — even cameras, cellphones and clothing shears! However, the
conclusion is that the mitzvah is limited to items used for food.

Kitchen or Leather?

Reuven is a leather worker who purchases a brand-new kitchen
knife that he intends to use exclusively for this leather work. Does this knife
require immersion in a mikveh?

Although this utensil was manufactured for food use, since
Reuven is now the owner and he purchased it for leather work, it is no longer a
food utensil.

The early authorities dispute whether someone who borrows
the knife from the owner to use it for food is required to immerse it. The
primary position contends that the borrower is not required to immerse the knife
(Hagahos Ashri, Avodah Zarah, 5:35; Shulchan Aruch, Yoreh Deah 120:8).
This approach understands that the halachic status of a utensil is
determined by its owner and not by the person borrowing it. There is, however,
a dissenting opinion that contends that since the owner himself would not be
allowed to use the knife for food, even temporarily, someone else may not
either (Issur Vaheter 58:89, quoted by Shach, Yoreh Deah 120:16).
Thus, the latter approach requires that the borrower immerse this knife before
using it for food. As a compromise position, some authorities conclude that one
should immerse this utensil, but should not recite a brocha before doing
so (Shach, Yoreh Deah 120:16).

However…

All this holds true as long as the owner, our leather worker,
uses the knife exclusively for non-food use. The owner may not use it for food,
even temporarily (Rema, Yoreh Deah 120:8). Furthermore, later
authorities note that the Shach implies that, should Reuven decide to
use the knife for food, albeit only once, he may not use the knife even for
non-food use
without first immersing it (Darchei Teshuvah 120:39,
quoting Ginzei Elimelech; Sefer TevilaskKeilim, page 104,
quoting Pri Eliyahu).

We see from this Shach a very interesting ruling. The
halachah is not that food use requires that the vessel be immersed. The halachah
is that a food utensil must be immersed before use – no matter what type of
use.

This last ruling means that someone who purchased a knife
that he intends to immerse, may not use it, even to open a package, before it
has been immersed.

We can therefore answer one of our opening questions:

“I have a knife that I use for my work, which is not food
related. May I occasionally slice a salami with the knife that I have never
immersed in a mikveh?”

Although many people may find this ruling to be surprising,
according to the Shach, you may not.

The vanilla cruet

At this point, I would like to discuss one of our opening
questions, an actual shaylah that I was asked: “We received a gift of a
glass cruet, a salad oil dispenser, that we doubt we will ever use for that
purpose. We decided, instead, to use it is a flower vase and were told that we
do not need to toivel it. Subsequently, we decided that we might use it
for soaking vanilla beans and alcohol to make our own natural vanilla extract.
Do we need to toivel it?”

This is an interesting question. I agree that if someone
receives a vessel that is usually klei seudah, but one does not intend to
use it for this purpose, there is no requirement to immerse it. Subsequently,
the individual decides that he might use the cruet to process vanilla flavor, a
use that would require immersing. (For reasons beyond the scope of this
article, I would suggest not reciting a brocha, when immersing the
cruet.) According to the Shach, once they decide to use the cruet for
making vanilla flavor, not only do they now need to immerse it, but they can no
longer use it for anything else. This is because a cruet is inherently a vessel
that should require immersion. The only reason they were not required to
immerse it until now was because they had decided not to use it for food. But
once they decide to use it for food, they may not use it for anything without
immersing it.

The salami knife

We can also now address a different question that was asked
above: “I have a knife that I use for my work, which is not food related. May I
occasionally slice a salami with the knife that I have never immersed in a mikveh?”

The answer is that, if this is a knife that was made for
food use, one would not be allowed to use it for food without immersing it. On
the other hand, if it is a box cutter, which is clearly not meant for food use,
we have no evidence that one is required to immerse it. There are sources in halachah
that state that an item that is not meant as klei seudah may be used
occasionally for food, even by the owner, without requiring tevilah
(see, for example, Darchei Teshuvah 120:70, 88).

Klei sechorah — “merchandise”

The halachic authorities note that a storekeeper does
not toivel vessels he is planning to sell, since for him they are not klei
seudah
, but merchandise. Later authorities therefore coined a term “klei
sechorah
,” utensils used as merchandise, ruling that these items do
not require immersion until they are purchased by the person intending to use
them (based on Taz, Yoreh Deah 120:10).

In the nineteenth century, a question was raised concerning
the definition of klei sechorah. When rail travel became commonplace,
enterprising entrepreneurs began selling refreshments at train stations. (No
club car on those trains!) A common occurrence was that Jewish vendors would
sell beer or other beverages at the stations, which they would serve to their
customers by the glassful. The question was raised whether these glasses
required immersion and whether one was permitted to drink from them when the
vendor presumably had not immersed them. Although it would seem that one may
not use them without tevilah, there are authorities who rule that these
vessels are considered klei sechorah for the merchant and that,
therefore, the customer may use them (Darchei Teshuvah 120:70, 88; Shu”t
Minchas Yitzchak
#1:44).

According to this approach, a restaurateur or caterer is not
required to immerse the utensils with which he serves his guests. Although most
authorities reject this approach (Minchas Shlomoh 2:66:14), I have found
many places where, based on this heter, hechsherim do not require
the owner to toivel his glassware, flatware and other items.

Conclusion

According to Rav Hirsch, metal vessels, which require
mankind’s mining, extracting and processing, represent man’s mastery over the
earth and its materials. Whereas vessels made of earthenware or wood involve
man merely shaping the world’s materials to fit his needs, the manufacture of
metal demonstrates man’s creative abilities to utilize natural mineral
resources to fashion matter into a usable form. Consuming food, on the other
hand, serves man’s most basic physical nature. Use of metal food vessels, then,
represents the intellectual aspect of man serving his physical self, which, in
a sense, is the opposite of why we were created; to use our physical self to
assist our intellect to do Hashem’s will. Specifically, in this
instance, the Torah requires that the items hereby produced be immersed in a mikveh,
to endow them with increased kedusha before they are put to food-use.
This demonstrates that, although one may use one’s intellect for physical
purposes, the product of one’s creative power must first be sanctified in order
that we focus on the spiritual.