Exodus 13:10-12

Young's Literal Translation

¹⁰ and thou hast kept this statute at its appointed season from days to days.

¹¹ `And it hath been, when Jehovah bringeth thee in unto the land of the Canaanite, as He hath sworn to thee and to thy fathers, and hath given it to thee,

¹² that thou hast caused every one opening a womb to pass over to Jehovah, and every firstling -- the increase of beasts which thou hast: the males [are] Jehovah's.