Given in place of the firstborn

16For they are wholly given to me from among the sons of Israel; in place of everyone who opens the womb, the firstborn of all the sons of Israel, I have taken them for myself.

17For every firstborn among the sons of Israel, among man and among beast, is mine. On the day I struck every firstborn in the land of Egypt, I consecrated them to myself.

18And I took the Levites in place of every firstborn among the sons of Israel.

19And I have given the Levites as a gift to Aaron and to his sons from among the sons of Israel, to do the service of the sons of Israel in the tent of meeting, and to make atonement for the sons of Israel, so that there may not be a plague among the sons of Israel when the sons of Israel come near to the holy place.