Exodus 12:13-15

13But the blood on your doorposts will serve as a sign, marking the houses where you are staying. When I see the blood, I will pass over you. This plague of death will not touch you when I strike the land of Egypt.

14“This is a day to remember. Each year, from generation to generation, you must celebrate it as a special festival to the Lord. This is a law for all time.

15For seven days the bread you eat must be made without yeast. On the first day of the festival, remove every trace of yeast from your homes. Anyone who eats bread made with yeast during the seven days of the festival will be cut off from the community of Israel.