Numbers 3:7-9

Amplified Bible

⁷ They shall carry out the duties for him and for the whole congregation before the Tent of Meeting, doing the service of the tabernacle. ⁸ They shall also take care of all the furnishings and utensils of the Tent of Meeting, and [attend to] the duties of the Israelites, doing the service of the tabernacle. ⁹ You shall give the Levites to Aaron and to his sons [as servants and helpers]; they are to be given wholly to him from among the Israelites.