17. For all the firstborn of the children of Israel are mine, both man and animal: on the day that I struck every firstborn in the land of Egypt I sanctified them for myself.
18. And I have taken the Levites for all the firstborn of the children of Israel.
19. And I have given the Levites as a gift to Aaron and to his sons from among the children of Israel, to do the service of the children of Israel in the tabernacle of meeting, and to make an atonement for the children of Israel: that there be no plague among the children of Israel, when the children of Israel come near unto the sanctuary.