Numbers 3:8-10

Young's Literal Translation

⁸ and they have kept all the vessels of the tent of meeting, and the charge of the sons of Israel, to do the service of the tabernacle;

⁹ and thou hast given the Levites to Aaron and to his sons; they are surely given to him out of the sons of Israel.

¹⁰ `And Aaron and his sons thou dost appoint, and they have kept their priesthood, and the stranger who cometh near is put to death.'