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 22:29

22:29 “Do not hold back offerings from your granaries or your vats. You must give me the firstborn of your sons.

Luke 2:7

2:7 And she gave birth to her firstborn son and wrapped him in strips of cloth and laid him in a manger, because there was no place for them in the inn.

Romans 8:29

8:29 because those whom he foreknew he also predestined to be conformed to the image of his Son, that his Son would be the firstborn among many brothers and sisters.