Exodus 13:8-14

8And thou shalt tell thy son in that day, saying, It is because of that which Jehovah did for me when I came forth out of Egypt. 9And it shall be for a sign unto thee upon thy hand, and for a memorial between thine eyes, that the law of Jehovah may be in thy mouth: for with a strong hand hath Jehovah brought thee out of Egypt. 10Thou shalt therefore keep this ordinance in its season from year to year.

11And it shall be, when Jehovah shall bring thee into the land of the Canaanite, as he sware unto thee and to thy fathers, and shall give it thee, 12that thou shalt set apart unto Jehovah all that openeth the womb, and every firstling which thou hast that cometh of a beast; the males shall be Jehovah’s. 13And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break its neck: and all the first-born of man among thy sons shalt thou redeem. 14And 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 Jehovah brought us out from Egypt, from the house of bondage: