Numbers 8:17-19

Modern English Version

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 I have taken the Levites instead of all the firstborn of the children of Israel. ¹⁹ I have given the Levites as a gift to Aaron and to his sons from among the children of Israel, to serve the service of the children of Israel in the tent of meeting and to make an atonement for the children of Israel, so there will be no plague among the children of Israel when the children of Israel approach the sanctuary.