Exodus 13:1-4
The Law of the Firstborn
13:1 The Lord spoke to Moses:
13:2 “Set apart to me every firstborn male – the first offspring of every womb among the Israelites, whether human or animal; it is mine.”
13:3 Moses said to the people, “Remember this day on which you came out from Egypt, from the place where you were enslaved, for the Lord brought you out of there with a mighty hand – and no bread made with yeast may be eaten.
13:4 On this day, in the month of Abib, you are going out.