Numbers 3:5-10

5The Lord spoke to Moses:

6“Bring the tribe of Levi near and present them to the priest Aaron to assist him.

7They are to perform duties for him and the entire community before the tent of meeting by attending to the service of the tabernacle.

8They are to take care of all the furnishings of the tent of meeting and perform duties for the Israelites by attending to the service of the tabernacle.

9Assign the Levites to Aaron and his sons; they have been assigned exclusively to him from the Israelites.

10You are to appoint Aaron and his sons to carry out their priestly responsibilities, but any unauthorized person who comes near the sanctuary is to be put to death.”