Exodus 13:11

⁹And it shall be to thee a sign upon thy hand and a memorial before thine eyes, that the law of the Lord may be in thy mouth, for with a strong hand the Lord God brought thee out of Egypt.

¹⁰And preserve ye this law according to the times of the seasons, from year to year.

— Exodus 13:11 —

¹²that thou shalt set apart every offspring opening the womb, the males to the Lord, every one that opens the womb out of the herds or among thy cattle, as many as thou shalt have: thou shalt sanctify the males to the Lord.

¹³Every offspring opening the womb of the ass thou shalt change for a sheep; and if thou wilt not change it, thou shalt redeem it: every firstborn of man of thy sons shalt thou redeem.