According
to Jewish tradition, the three Sabbath meals (Friday night, Saturday
lunch, and Saturday late afternoon) and two holiday meals (one at
night and lunch the following day) each begin with two complete loaves
of bread.
This "double loaf" (in Hebrew: lechem mishneh) commemorates
the manna that fell from the heavens when the Israelites wandered
in the desert for forty years after the Exodus from Egypt.
The
manna did not fall on the Sabbath or holidays; instead, a double portion
would fall the day before the holiday or sabbath. hunks of bread,
recognizable by their traditional braided style (although some more
modern recipes are not braided) that are commonly referred to as challah.