Exodus 12:13-15

131The blood shall be a sign for you on the houses where you 2live; and when I see the blood I will pass over you, and no plague will come upon you 3to destroy you when I strike the land of Egypt.

14‘Now 4this day shall be 5a memorial to you, and you shall celebrate it as a feast to the Lord; throughout your generations you are to celebrate it as 67a permanent ordinance. 15For 8seven days you shall eat unleavened bread, but on the first day you shall remove dough with yeast from your houses; for whoever eats anything with yeast from the first day until the seventh day, 9that 10person shall be cut off from Israel.