Exodus 13:2 "Consecrate to me every firstborn male. The first offspring of every womb among the Israelites belongs to me, whether man or animal."
Exodus 22:29, "You must give me the firstborn of your sons."
Exodus 34:19-20, "The first offspring of every womb belongs to me, including all the firstborn males of your livestock, whether from herd or flock. Redeem the firstborn donkey with a lamb, but if you do not redeem it, break its neck. Redeem all your firstborn sons."
Numbers 3:12-13, "I have taken the Levites from among the Israelites in place of the first male offspring of every Israelite woman. The Levites are mine, for all the firstborn are mine. When I struck down all the firstborn in Egypt, I set apart for myself every firstborn in Israel, whether man or animal. They are to be mine. I am the LORD."
Numbers 3:41 "Take the Levites for me in place of all the firstborn of the Israelites, and the livestock of the Levites in place of all the firstborn of the livestock of the Israelites. I am the LORD."
Numbers 1:50-51 "Appoint the Levites to be in charge of the tabernacle of the Testimony—over all its furnishings and everything belonging to it. They are to carry the tabernacle and all its furnishings; they are to take care of it and encamp around it. Whenever the tabernacle is to move, the Levites are to take it down, and whenever the tabernacle is to be set up, the Levites shall do it."