Num Numbers, chapter Book of Numbers, chapter 3
The Duties of the Levites
They are to perform duties for him and for the whole congregation before the Tent of Meeting, attending to the service of the tabernacle. They shall take care of all the furnishings of the Tent of Meeting and fulfill obligations for the Israelites by attending to the service of the tabernacle.Lev 8:35
Assign the Levites to Aaron and his sons; they have been given exclusively to him3:9 Most MT manuscripts; some MT manuscripts, SP, and LXX (see also Numbers 8:16) to Me from among the Israelites. Num 8:19