The Mayim Shelanu Saga

Question #1: Who owns it?

Who owns mayim shelanu?

Question #2: Occupation or Preoccupation

“May I do something else while I bake my matzohs?”

Question #3: Mayim shelanu in Montevideo

“I have some experience at baking my own matzohs, and I will be spending Pesach in Uruguay. I intend to bake my own matzohs for the Seder. Must I use mayim shelanu for baking matzohs in the southern hemisphere?”


Among the various instructions that the Gemara provides for baking matzoh is a requirement to use mayim shelanu, which should be translated as water that rested. This article will discuss the halachic requirements that Chazal instituted.

Who bakes the matzoh?

In the time of the Gemara, matzohs were baked fresh daily, and we see that the kneading and baking was usually the responsibility of the women of the household. Until fairly recently, this was common practice in many Sefardic communities, but among Ashkenazim, matzoh production has in most places become a commercial enterprise, since at least the nineteenth century. Today, few people bake their own matzohs, although I know people in Eretz Yisroel who still do so.

What is mayim shelanu?

Let us begin by quoting the Gemara that forms the basis of our discussion:

Rabbi Yehudah said, “A woman should knead dough for matzoh only with mayim shelanu.” Rav Masneh taught this in a public lecture in Papunia, a town in Bavel where the spoken language was Aramaic. Rav Masneh quoted Rabbi Yehudah’s exact Hebrew words, mayim shelanu, which can also mean our water. The next day, all the people came to him with their buckets, requesting that Rav Masneh supply them with his water, so that they could bake their matzohs. He then explained to them that he had meant water that rested, this time using the Aramaic words, maya devisu (Pesachim 42a).

The authorities debate whether Rav Masneh was teaching this as part of the traditional Shabbos Hagadol drosha, whose primary halachic purpose is to educate people regarding the details of the laws of Pesach, or whether he was delivering this discourse on Yom Tov. If it was on Yom Tov, why would Rav Masneh have waited until Yom Tov to tell them about an essential practice necessary to bake kosher-for-Pesach matzohs? The probable answer is that Rav Masneh was a visitor in Papunia on Yom Tov and chose to discuss this topic when asked to give a guest lecture.

Why the anecdote?

The rishonim ask why the Gemara needs (or should I say kneads?) to mention the story of Rav Masneh (Yerei’im). They do not answer that it is to teach us to have a sense of humor. What was the purpose of the story? There are several interesting answers to this question, two of which we will discuss at the end of this article.

But first, let us return to the continuation of the passage of Gemara:

“Rava taught in a public lecture: a woman should not knead her dough for matzoh under the sun, nor may she use hot water, even if it was heated only by being exposed to sunlight, nor may she use water that appears to be room temperature, if it was swept out of a water heater whose coals were removed. She should be careful not to ‘raise her hands’ from the oven until she completes making the matzoh,” which is another way of saying that she should remain focused on the matzoh production until it is finished, and certainly not do anything else in the interim (Pesachim 42a).

Occupation or Preoccupation

Thus, we can now answer one of our opening questions: “May I do something else while I bake my matzohs?”

The answer is that one may not.

After the fact

The Gemara then asks what is the halacha if someone made matzoh using water that did not meet the standards mentioned above, and cites a dispute between Mar Zutra and Rav Ashi whether the matzoh may be used. Mar Zutra permitted the matzoh thus prepared, whereas Rav Ashi prohibited it. The halachic authorities rule according to Rav Ashi, that this matzoh may not be used. The authorities then debate whether this ruling applies only to the latter cases — one who kneaded the matzoh outdoors or who used warm water — or does it apply even to someone who kneaded matzoh with water that was not mayim shelanu. Rashi is quoted as having ruled that matzoh prepared with water that was not mayim shelanu is permitted bedei’evid, after the fact, whereas most authorities prohibit this matzoh.

Mayim shelanu wherefore?

Why did Chazal prohibit using water for matzoh baking, unless it rested? The poskim cite two main approaches.

According to Rashi, mayim shelanu is required because, during the winter months, the sun traverses the earth much closer to the earth than it does in the summer. Thus, the areas of the earth in which there are open bodies of water become heated to a much greater degree in the winter than they are in the summer, making the water too warm for baking matzohs. Since Pesach in the northern hemisphere is at the end of the winter, it arrives when outside water is warmer than desired for matzoh baking, until it has had ample time to cool. Since the Gemara mentions specifically that the water was lanu, many authorities maintain that the water must rest in a cool place for a minimum of twelve hours (Gra).

Mayim shelanu in the southern hemisphere

It would seem that, according to Rashi, there is no need for mayim shelanu when making matzoh before Pesach in Argentina, Australia, South Africa and anywhere else in the southern hemisphere, since, in that part of the world, Pesach falls at the end of the summer, not the end of the winter. Similarly, someone baking Pesach matzohs in the summer months in the northern hemisphere would not require mayim shelanu. Although this last piece of information may not be germane to any existing kosher lePesach matzoh bakeries, it will be of interest to those producing matzoh for the grain offerings, the menachos, to be offered in the Beis Hamikdash when it is rebuilt, speedily and in our days, since, with only two exceptions, they may not be chometz.

River water

The rishonim quote that Rashi himself held that mayim shelanu is required only when using water from a spring or a cistern, but not when using water drawn from a river. Some explain that this is because we can assume that it has already had sufficient time to cool (Responsum of Rashi, quoted by Ravyah #485, as explained by Kolbo #48). However, later authorities (Ravyah #485; Shulchan Aruch, Orach Chayim 455:1) do not accept this lenient ruling and require that river water wait several hours before use for baking matzohs.

Here comes the sun!

The second reason for mayim shelanu is that provided by Rav Eliezer of Metz, a disciple of Rabbeinu Tam and the author of Sefer Ye’rei’im, an important early halachic source. The Ye’rei’im explains that one should not use water for matzohs unless it rested, because water drawn at night from underground was heated by the sun, since the sun is on the other side of the earth at night. He rules that water drawn at the very beginning of the night can be used immediately, since it has not yet had opportunity to become hot. This lenience applies to water drawn at the very end of the day, during twilight (bein hashemashos), or at the beginning of the night.

Luck of the draw

Among the major halachic commentaries to the Tur and the Shulchan Aruch, we find three different ways of understanding the Ye’rei’im’s position:

  1. According to the Taz, the Ye’rei’im required that matzohs be baked only with water that was drawn during the evening, as described above. Any water drawn at any other time is considered to have become heated and may no longer be used for matzoh production. The Taz contends that one may not use for baking matzohs any water that was ever known to be hot, even if it was subsequently cooled and allowed to rest. Several other authorities, such as the Hagahos Semaq 222:9, and the Mizrachi, also rule this way (as understood by the Beis Yosef and the Taz.) The reason why we refer to the water as “water that rested overnight” is because usually one needs to draw it at least a day before one will use it, and prior to the night.
  2. According to the Bach’s understanding of the Ye’rei’im, one may never use water drawn at night, but water drawn in the daytime becomes usable after it has been allowed to cool until the following morning.
  3. According to the Beis Yosef’s understanding of the Ye’rei’im, water drawn any time other than twilight becomes permissible for matzoh production after it has been in a cool place overnight. Thus, water drawn at night becomes usable the morning after the following night, whereas water drawn in the daytime becomes usable the following morning.

According to all three opinions, the Ye’rei’im permitted immediate use of water that was drawn in the evening, whereas Rashi required this water to rest overnight. According to Rashi, water drawn in the daytime is acceptable for matzoh production after it has been left for twelve hours in a cool place, whereas according to the Ye’rei’im (as understood by the Beis Yosef and Bach), this water may not be used until the following morning, which is considerably more than 12 hours. The halachic authorities rule that lechatchilah one should draw mayim shelanu in the evening and then wait overnight until one uses it, which is basically following the stringencies of both Rashi and the Ye’rei’im.

This means that one draws water from a spring, well, or river immediately before twilight and leaves it in a cool place for a minimum of one complete night to allow it to cool (Shulchan Aruch Orach Chayim 455:1 and commentaries). One may draw water for several days at one time (Shulchan Aruch 455:1), provided one draws the water immediately before twilight and then stores it in a cool place, although some poskim prefer that the water be drawn freshly each night (Maharil quoted by Ba’er Heiteiv 455:7). The water should not be drawn or stored in a metal vessel since metal conducts heat and warms the water (Magen Avraham 455:9). In addition, the water should not be drawn or stored in a vessel that has been used previously to hold other liquids since some liquid may mix with the water, and this may cause the dough to rise faster than otherwise (Magen Avraham ibid.). Many contemporary poskim discourage using tap water for matzos because of concern that fluoride and other chemicals introduced into the water may cause the dough to rise more quickly (see Mo’adim U’zemanim 3:261). It is important to note that the requirement for mayim shelanu is not only for the matzos eaten at the Seder, but also for all matzos eaten during the entire Pesach.

Rav Masneh’s lecture

At this point, let us return to a previous question: The Gemara tells us the amusing anecdote concerning the misunderstanding that resulted from Rav Masneh’s lecture, where the people misunderstood mayim shelanu to mean Rav Masneh’s water, until he clarified that it meant water that rested overnight.  Why is it important for the Gemara to tell us this story? From the Ye’rei’im onward, many halachic authorities discuss this question, providing a variety of answers. Some explain that Rav Masneh delivered this lecture on Yom Tov, and they infer the following conclusion: If matzoh made without mayim shelanu is prohibited, Rav Masneh would have left the people of Papunia with nothing to eat – they would have had to destroy all the matzoh they had already produced, since it was not made using mayim shelanu, and they would have had nothing to eat the next day either, since they had no water with which to bake. Since the Gemara mentions nothing of the hardship that was imposed by his ruling, we should conclude that the Gemara’s purpose is to teach that mayim shelanu is required only lechatchilah, but, after the fact, matzoh made using water that was not mayim shelanu is permitted (Sefer Ye’rei’im).

Others contend that Rav Masneh taught this as part of the Shabbos Hagadol drosha, and that Pesach that year began on Sunday night. (In our current calendar implemented by Hillel Hanasi, Pesach cannot begin on Sunday night. However, Rav Masneh lived at a time when the central Beis Din still determined the calendar on a monthly basis, and, in that era, Pesach could begin on any day of the week.) On Sunday, the people came to fetch water from Rav Masneh, intending to bake their matzohs in the afternoon. This was the common practice in earlier days – matzohs for the Seder were not baked until the afternoon of Erev Pesach, a practice mentioned in Shulchan Aruch and still practiced by many.

Now that they had no water with which to bake their matzohs, what were they to do for matzohs for the Seder? Since the Gemara does not say that they had a matzoh-less Seder, there are a few options:

  1. As we mentioned above, it could be that mayim shelanu is only a lechatchilah rule, but, after the fact, one who has no mayim shelanu can bake matzohs with room temperature water (Raavyah; Semag).
  2. As long as several hours have elapsed since the water was drawn, it is called mayim shelanu, regardless as to when it was drawn. Thus, having heard Rav Masneh’s ruling, the people immediately drew water and began timing the cooling off period. Towards evening, they baked their matzohs (Ravyah #485), or possibly even in the middle of the Seder!

As we all know, matzoh is made of only two ingredients, kosher-for-Pesach flour and water. Although few of us bake our own matzohs, we now know that there are halachos germane to what water one must use for baking matzohs. This provides some information that enables us to understand what is involved in the kashrus of one of the two ingredients in the manufacture of matzoh.

Baking with Hallel!

While baking matzoh on erev Pesach, there is a custom of singing Hallel with tremendous emotion. The moments that we recite Hallel then, and on Pesach itself, can encapsulate the most fervent experience of His closeness. Reliving Hashem’s miracles rekindles the cognizance of Hashem’s presence. In the merit of joyously performing the mitzvos of Seder night, may we soon see the return of the Divine Presence to Yerushalayim and the rededication of the Beis HaMikdash, and be zocheh to fulfill all of these mitzvos, including the korban Pesach!