Exodus 13:10

Unleavened bread shall be eaten throughout the seven days; and no leavened bread shall be seen with you. No yeast shall be seen with you, within all your borders.

You shall tell your son in that day, saying, ‘It is because of that which the LORD did for me when I came out of Egypt.’

It shall be for a sign to you on your hand, and for a memorial between your eyes, that the LORD’s law may be in your mouth; for with a strong hand the LORD has brought you out of Egypt.

“It shall be, when the LORD brings you into the land of the Canaanite, as he swore to you and to your fathers, and will give it to you,

that you shall set apart to the LORD all that opens the womb, and every firstborn that comes from an animal which you have. The males shall be the LORD’s.

Every firstborn of a donkey you shall redeem with a lamb; and if you will not redeem it, then you shall break its neck; and you shall redeem all the firstborn of man among your sons.