Exodus 13:11 KJV

9And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the LORD’s law may be in thy mouth: for with a strong hand hath the LORD brought thee out of Egypt.

10Thou shalt therefore keep this ordinance in his season from year to year.

11And it shall be when the LORD shall bring thee into the land of the Canaanites, as he sware unto thee and to thy fathers, and shall give it thee,

12That thou shalt set apart unto the LORD all that openeth the matrix, and every firstling that cometh of a beast which thou hast; the males shall be the LORD’s.

13And every firstling of an ass thou shalt redeem with a lamb; and if thou wilt not redeem it, then thou shalt break his neck: and all the firstborn of man among thy children shalt thou redeem.