Numbers 3:8-10

King James Version

⁸ And they shall keep all the instruments of the tabernacle of the congregation, and the charge of the children of Israel, to do the service of the tabernacle.

⁹ And thou shalt give the Levites unto Aaron and to his sons: they are wholly given unto him out of the children of Israel.

¹⁰ And thou shalt appoint Aaron and his sons, and they shall wait on their priest's office: and the stranger that cometh nigh shall be put to death.