Numbers 3:5-8

Then the LORD spoke to Moses, saying, “Bring the tribe of Levi near and present them before Aaron the priest, so that they may serve him. They shall carry out the duties for him and for the whole congregation before the Tent of Meeting, doing the service of the tabernacle. 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.