Exodus 12:17-20

17So you are to observe the Feast of Matzot, for on this very same day have I brought your ranks out of the land of Egypt. Therefore you are to observe this day throughout your generations as an eternal ordinance.

18During the first month in the evening of the fourteenth day of the month, you are to eat matzot , until the evening of the twenty-first day of the month.

19For seven days no hametz is to be found in your houses, for whoever eats hametz, that soul will be cut off from the congregation of Israel, whether he is an outsider or one who is born in the land.

20You are to eat no hametz; in all your houses you are to eat matzot .”