Numbers 8:18

¹⁶For these are given to me for a present out of the midst of the children of Israel: I have taken them to myself instead of all the firstborn of the sons of Israel that open every womb.

¹⁷For every firstborn among the children of Israel is mine, whether of man or beast: in the day in which I smote every firstborn in the land of Egypt, I sanctified them to myself.

— Numbers 8:18 —

¹⁹And I gave the Levites presented as a gift to Aaron and his sons out of the midst of the children of Israel, to do the service of the children of Israel in the tabernacle of witness, and to make atonement for the children of Israel: thus there shall be none among the sons of Israel to draw nigh to the holy things.

²⁰And Moses and Aaron, and all the congregation of the children of Israel, did to the Levites as the Lord commanded Moses concerning the Levites, so the sons of Israel did to them.