Exodus 13:1-3

Then the Lord spoke to Moses, saying,

“Sanctify to Me every firstborn, the firstborn of every womb among the sons of Israel, among people and animals alike; it belongs to Me.”

And Moses said to the people, “Remember this day in which you departed from Egypt, from the house of slavery; for by a powerful hand the Lord brought you out from this place. And nothing with yeast shall be eaten.