Numbers 1:49-52

49“Do not number the tribe of Levi in the census with the other Israelites. 50Instead, you are to appoint the Levites over the tabernacle of the Testimony, all its furnishings, and everything in it. They shall carry the tabernacle and all its articles, care for it, and camp around it.

51Whenever the tabernacle is to move, the Levites are to take it down, and whenever it is to be pitched, the Levites are to set it up. Any outsider who goes near it must be put to death.

52The Israelites are to camp by their divisions, each man in his own camp and under his own standard.