Treasury of Scripture Knowledge
"Set apart to me every firstborn male -- the first offspring of every womb among the Israelites, whether human or animal; it is mine."
"Do not hold back offerings from your granaries or your vats. You must give me the firstborn of your sons.
The firstborn of every womb which they present to the Lord, whether human or animal, will be yours. Nevertheless, the firstborn sons you must redeem, and the firstborn males of unclean animals you must redeem.
The first of all the first fruits and all contributions of any kind will be for the priests; you will also give to the priest the first portion of your dough, so that a blessing may rest on your house.
(just as it is written in the law of the Lord, "Every firstborn male will be set apart to the Lord"),