Exodus 13:13-14

But every first offspring of a donkey you shall redeem with a lamb, but if you do not redeem it, then you shall break its neck; and every firstborn of man among your sons you shall redeem. And it shall be when your son asks you in time to come, saying, ‘What is this?’ then you shall say to him, ‘With a powerful hand the LORD brought us out of Egypt, from the house of slavery.