Exodus 13:14 in the King James Version
And it shall be when thy son asketh thee in time to come, saying, What is this? that thou shalt say unto him, By strength of hand the LORD brought us out from Egypt, from the house of bondage:
Context
13 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.
14 It shall be, when your son asks you in time to come, saying, ‘What is this?’ that you shall tell him, ‘By strength of hand the LORD brought us out from Egypt, from the house of bondage.
15 When Pharaoh stubbornly refused to let us go, the LORD killed all the firstborn in the land of Egypt, both the firstborn of man, and the firstborn of livestock. Therefore I sacrifice to the LORD all that opens the womb, being males; but all the firstborn of my sons I redeem.’