In the 1st month, on the 14th day of the month at evening, you shall eat unleavened bread, until the 21st day at evening. For 7 days no leaven shall be found in your houses, since whoever eats what is leavened, that same person shall be cut off from the congregation of Israel, whether he is a stranger or a native of the land. You shall eat nothing leavened; but in all your dwellings, you shall eat unleavened bread. - Ex 12:14-20,13:3-10,23:14-17,34:18; Lev 23:6-8; Num 28:17; Deut 16:3-4,8,16