We don’t write a lot about halachic matters in this blog, but I happen to be studying the halacha of Kiddush and Hamotzi, and I happened to come across a box of books with a book in English called The Radiance of Shabbos, which includes a chapter on Lechem Mishneh, so it seemed appropriate to write down a few points.
Why Lechem Mishneh?
One of the heavenly miracles that took place on a daily basis during the 40-year sojourn in the desert wilderness was manna, which descended from heaven every morning, to provide that day’s sustenance. On Fridays, a double portion fell, and none on Shabbos. As an act of remembrance of this double portion, we start each meal with two loaves of bread (typically challah bread), which are referred to as Lechem Mishneh.
Interestingly, there is a debate among the Achronim whether the obligation is based on Torah law or Rabbinical law.
Both men and women are obligated, and parents must train children to observe the practice as well.
Two whole loaves must be used. How do you ascertain whether a split or crack loaf is considered “whole?” If it’s intact enough so that if you lift the bread by the weaker part and it doesn’t break in two, it’s still considered whole. According to some authorities, if a bit of the bread is missing, as long as it constitutes no more than 1/48 of the loaf, the bread can still be used for Lechem Mishneh.
What do you do if you don’t have two loaves?
If you do not have two whole loaves, you should fulfill the obligation of Lechem Mishneh using a whole loaf and a cut loaf.
Another possibility is to piece together a broken loaf using toothpicks, in such a manner that the toothpicks are not highly visible.
If you have no whole loaves and no way of piecing them together, partial loaves are better than nothing. In fact, if you have no bread at all, you should recite Hamotzi on whole cakes, donuts, etc.
The obligation on Yom Tov
Lechem Mishneh is also an obligation on Yom Tov. The only difference is that on Shabbat many follow the Kabbalistic practice of cutting the bottom challah on Friday night, and the top one for the daytime meals, whereas this custom does not apply on Yom Tov, so we always cut the upper loaf (Rema O.C. 274:1).
Can I use bagels for Lechem Mishneh?
Rabbi Yirmihohu Kagenoff has a fascinating discussion on the question of whether you can use bagels for Lechem Mishneh:
"To answer this question, let us spend a moment researching how bagels are made. The old-fashioned method of making bagels was by shaping dough into the well-known bagel with-a-hole circle, boiling them very briefly and then baking the boiled dough.
"Modern bagel factories do not boil the dough, but instead steam the shaped bagels prior to baking them, which produces the same texture and taste one expects when eating a bagel, creates a more consistent product and lends itself more easily to a mass production process. In either way of producing bagels, the halacha is that their proper brochah is Hamotzi, because they are basically baked products (Shulchan Aruch, Orach Chayim 168:14). Since halacha treats them as regular bread, they may be used for Lechem Mishneh on Shabbos and Yom Tov."
By the way, there is also a very famous commentary on the Mishneh Torah called Lechem Mishneh, written by Rabbi Abraham Hiyya de Boton, of Polia, Eretz Yisrael and Constantinople.