From when we were children, we all learnt the famous melody that lists all of the 14 different functions that we perform at the Seder. This order of simanim, from which the Seder draws its name, originates from the Kadmonim. However, there is one item on the list that seems to be unnecessary. That is Yachatz, where we break the middle matzah. Now, the Gemara (Pesachim 115b) does state that a broken matzah is needed for the Seder, however why do we need to break it at the Seder? Why could we not have made good use of one of the many broken pieces that are included for free in each box of matzah? Why could we not have set the table with two complete matzos and one broken one? Ultimately, this would eliminate the siman in the Seder known as Yachatz. So, why is Yachatz necessary?
In fact, the Be’er Haitev (Orach Chaim 475:19) cites a minhag that some had to bring four matzos to the table, in case one would break. This again begs the question, why is it important to actually physically break the matzah at the Seder?
It is interesting to note that the Rambam in Hilchos Chametz U’Matzah (8:6) say that Yachatz is performed right before the matzah is eaten during Motzie Matzah, and not before Maggid. It is however broken at the Seder and the same question remains.
The Machzor Vitri was authored by a talmid of Rashi. In this work there is a section titled “Seder Aruch from Rabbenu Shlomo bar Yitzchak (Rashi).” This is a list of simanim that we perform at the Seder and a brief explanation of what is done at each one (the list begins on page 281 in volume 1). Yachatz dos not appear on this list! To reiterate, he lists; Kadeish, Orchatz, Karpas, Maggid….
When it comes to Motzie Matzah he explains that one recites a berachah of Hamotzie on the complete matzah and the berachah of Al Achilas Matzah on the broken matzah. Apparently, according to this opinion, as we mentioned from the Gemara, a broken matzah was used for the Seder. The only difference is that it was not actually broken at the Seder.
While this opinion is absolved of our question, and on the contrary is exactly the way we would understand that it should be, this is not the prevalent minhag. The minhag that is mentioned by many Rishonim, and as is practiced in practically every home observing a Seder today, is to break the matzah before Maggid. And we need to understand why.
I saw an answer to this based on an explanation of the Netziv. In his sefer Meishiv Davar (1:21) he writes that at his father-in-law’s house (Rav Itzella m’Volozhin) if a guest would come late to the seudah on Shabbos or Yom Tov his shver would hand him two slices of the bread that was already cut for lechem mishneh. Although for lechem mishneh one must have to complete pieces of bread, not slices, nevertheless it was two pieces and thus it was a kiyum of lechem mishneh.
The Netziv asked that this is contradicted from several sources that are clear that once a challah is cut it can no longer be used for lechem mishneh (see Tosafos, Berachos 39a, s.v. v’hilchisa, and Rema, Orach Chaim 291:4).
The Netziv answered that there is a difference between a piece of bread that was cut already in front of you, and one that was cut from beforehand. If a loaf of bread is cut in front of you it is no longer considered whole and thus cannot be used to fulfill the mitzvah of lechem mishneh. However, if a loaf was already split, the pieces can be used as lechem mishneh.
Based on this concept perhaps we can explain why there is an minhag to break the matzah at the Seder. As we mentioned above, the Gemara says that one must use a broken matzah at the Seder. If the matzah was already broken from before the Seder, it may not be considered “broken.” Thus, we must break the matzah at the Seder in order to ensure that it will be a broken matzah.