Exodus 13:13-15

Darby Translation

¹³ And every firstling of an ass shalt thou ransom with a lamb; and if thou do not ransom it, thou shalt break its neck; and every firstborn of a man among thy sons shalt thou ransom.

¹⁴ And it shall be when thy son asketh thee in time to come, saying, What is this? that thou shalt say to him, With a powerful hand Jehovah brought us out from Egypt, out of the house of bondage.

¹⁵ And it came to pass, when Pharaoh stubbornly refused to let us go, that Jehovah slew all the firstborn in the land of Egypt, both the firstborn of men and the firstborn of cattle: therefore I sacrifice to Jehovah all that breaketh open the womb—being males; and every firstborn of my children I ransom.