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.
"Every firstborn of the womb belongs to me, even every firstborn of your cattle that is a male, whether ox or sheep.
because all the firstborn are mine. When I destroyed all the firstborn in the land of Egypt, I set apart for myself all the firstborn in Israel, both man and beast. They belong to me. I am the Lord."
For they are entirely given to me from among the Israelites. I have taken them for myself instead of all who open the womb, the firstborn sons of all the Israelites.
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.
Then she will remain thirty-three days in blood purity. She must not touch anything holy and she must not enter the sanctuary until the days of her purification are fulfilled.