Exodus 13:1-3

Revised Standard Version Catholic Edition

13 The Lord said to Moses, ² “Consecrate to me all the first-born; whatever is the first to open the womb among the people of Israel, both of man and of beast, is mine.”

The Festival of Unleavened Bread

³ And Moses said to the people, “Remember this day, in which you came out from Egypt, out of the house of bondage, for by strength of hand the Lord brought you out from this place; no leavened bread shall be eaten.