Exodus 13:6-16

6Seven days thou shalt eat unleavened bread, and in the seventh day shall be a feast to Jehovah. 7Unleavened bread shall be eaten throughout the seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee, in all thy borders. 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: 15and it came to pass, when Pharaoh would hardly let us go, that Jehovah slew all the first-born in the land of Egypt, both the first-born of man, and the first-born of beast: therefore I sacrifice to Jehovah all that openeth the womb, being males; but all the first-born of my sons I redeem. 16And it shall be for a sign upon thy hand, and for frontlets between thine eyes: for by strength of hand Jehovah brought us forth out of Egypt.