Exodus 12:15-18 - The Festival Of Unleavened Bread

¹⁵ You are to eat unleavened bread for seven days. On the first day be sure to remove all the leaven from your houses, because any person who eats anything leavened from the first day until the seventh will be cut off from Israel. ¹⁶ Also, on the first day you're to hold a holy assembly, and on the seventh day you're to hold a holy assembly. No work is to be done during those days, except for preparing what is to be eaten by each person.

¹⁷ ""You are to observe the Festival of Unleavened Bread, since on this very day I brought your tribal divisions from the land of Egypt. You are to observe this day from generation to generation as a perpetual ordinance. ¹⁸ In the first month, from the evening of the fourteenth day of the month until the evening of the twenty-first day of the month, you are to eat unleavened bread.