Exodus 12:17

14 And this day is to be kept in your memories: you are to keep it as a feast to the Lord through all your generations, as an order for ever.

15 For seven days let your food be unleavened bread; from the first day no leaven is to be seen in your houses: whoever takes bread with leaven in it, from the first till the seventh day, will be cut off from Israel.

16 And on the first day there is to be a holy meeting and on the seventh day a holy meeting; no sort of work may be done on those days but only to make ready what is necessary for everyone's food.

17 So keep the feast of unleavened bread; for on this very day I have taken your armies out of the land of Egypt: this day, then, is to be kept through all your generations by an order for ever.

18 In the first month, from the evening of the fourteenth day, let your food be unleavened bread till the evening of the twenty-first day of the month.

19 For seven days no leaven is to be seen in your houses: for whoever takes bread which is leavened will be cut off from the people of Israel, if he is from another country or if he is an Israelite by birth.

20 Take nothing which has leaven in it; wherever you are living let your food be unleavened cakes.