Exodus 34:18-21; Exodus 34:25

18 “Celebrate the Festival of Unleavened Bread. For seven days eat bread made without yeast, as I commanded you. Do this at the appointed time in the month of Aviv, for in that month you came out of Egypt.

19 “The first offspring of every womb belongs to me, including all the firstborn males of your livestock, whether from herd or flock.

20 Redeem the firstborn donkey with a lamb, but if you do not redeem it, break its neck. Redeem all your firstborn sons. “No one is to appear before me empty-handed.

21 “Six days you shall labor, but on the seventh day you shall rest; even during the plowing season and harvest you must rest.

25 “Do not offer the blood of a sacrifice to me along with anything containing yeast, and do not let any of the sacrifice from the Passover Festival remain until morning.