Bible: Ex. 13:2, 12, 15

13:2 Set apart 1  to me every firstborn male – the first offspring of every womb 2  among the Israelites, whether human or animal; it is mine.” 3 

13:12 then you must give over 4  to the Lord the first offspring of every womb. 5  Every firstling 6  of a beast that you have 7 the males will be the Lord’s. 8  13:15 When Pharaoh stubbornly refused 9  to release us, the Lord killed all the firstborn in the land of Egypt, from the firstborn of people to the firstborn of animals. 10  That is why I am sacrificing 11  to the Lord the first male offspring of every womb, but all my firstborn sons I redeem.’
NET Bible Study Environment