Exodus 13:15

and that you may recount in the hearing of your son and of your grandson, how I dealt severely with the Egyptians, and how I put My signs among them, that you may know that I am Yahweh.”

“And it will be when your children say to you, ‘What is the meaning of this new slavery to you?’

“Sanctify to Me every firstborn, the first offspring of every womb among the sons of Israel, both of man and beast; it belongs to Me.”

“And you shall redeem with a lamb the first offspring from a donkey; and if you do not redeem it, then you shall break its neck. You shall redeem all the firstborn of your sons. None shall appear before Me empty-handed.

“For the redemption price of the 273 of the firstborn of the sons of Israel who are in excess beyond the Levites,

“For every firstborn among the sons of Israel is Mine, among the men and among the animals; on the day that I struck down all the firstborn in the land of Egypt I sanctified them for Myself.

“Every first issue of the womb of all flesh, whether man or animal, which they bring near to Yahweh, shall be yours; nevertheless the firstborn of man you shall surely redeem, and the firstborn of unclean animals you shall redeem.

He also struck down all the firstborn in their land, The first of all their vigor.