Numbers 1:47-53

47The Levites, however, were not counted by the tribe of their ancestors,

48for Adonai told Moses saying,

49“Definitely you are not to number the tribe of Levi, nor take the sum of them among Bnei-Yisrael.

50Instead, you are to appoint the Levites over the Tabernacle of the Testimony, over all its implements and all pertaining to it. They are to carry the Tabernacle and all its utensils, tend to it and camp around it.

51Whenever the Tabernacle sets out, the Levites are to dismantle it, and whenever the Tabernacle is pitched, the Levites are to set it up. But the commoner who comes near to it must be put to death.

52Bnei-Yisrael will encamp, each man with his own camp, each with his own standard, according to their own divisions.

53The Levites are to camp around the Tabernacle of the Testimony, so that there will be no wrath unleashed on the community of Bnei-Yisrael. So the Levites are to maintain care of the Tabernacle of the Testimony.