Exodus 13:2

13:2 “Set apart to me every firstborn male – the first offspring of every womb among the Israelites, whether human or animal; it is mine.”

Exodus 13:12

13:12 then you must give over to the Lord the first offspring of every womb. Every firstling of a beast that you have – the males will be the Lord’s.

Exodus 34:19

34:19 “Every firstborn of the womb belongs to me, even every firstborn of your cattle that is a male, whether ox or sheep.