Matzah (Hebrew: מצה ) is an unleavened bread.It is eaten only on Passover. The Matzah was one of the foods the Jews were commanded to eat in Egypt along with the paschal lamb as mentioned in Exodus 12:8:
" וְאָכְלוּ אֶת-הַבָּשָׂר, בַּלַּיְלָה הַזֶּה: צְלִי-אֵשׁ וּמַצּוֹת, עַל-מְרֹרִים יֹאכְלֻהוּ."
" And they shall eat the flesh in that night, roast with fire, and unleavened bread; with bitter herbs they shall eat it."