Exodus 12:17

13 The blood on the houses where you are staying will distinguish them; when I see the blood, I will pass over you. No plague will fall on you to destroy you when I strike the land of Egypt.

14 And this day will be a memorial for you, and you are to celebrate it as a feast to the LORD, as a permanent statute for the generations to come.

15 For seven days you must eat unleavened bread. On the first day you are to remove the leaven from your houses. Whoever eats anything leavened from the first day through the seventh must be cut off from Israel.

16 On the first day you are to hold a sacred assembly, and another on the seventh day. You must not do any work on those days, except to prepare the meals—that is all you may do.

17 So you are to keep the Feast of Unleavened Bread, for on this very day I brought your divisions out of the land of Egypt. You must keep this day as a permanent statute for the generations to come.

18 In the first month you are to eat unleavened bread, from the evening of the fourteenth day until the evening of the twenty-first day.

19 For seven days there must be no leaven found in your houses. If anyone eats something leavened, that person, whether a foreigner or native of the land, must be cut off from the congregation of Israel.

20 You are not to eat anything leavened; eat unleavened bread in all your homes.”

21 Then Moses summoned all the elders of Israel and told them, “Go at once and select for yourselves a lamb for each family, and slaughter the Passover lamb.

Read all of Exodus 12