Numbers 1:51-53

Amplified Bible

⁵¹ When the tabernacle is to go forward, the Levites shall take it down; and when the tabernacle is to [be set up for] camp, the Levites shall set it up. But the layman (non-Levite) who approaches the tabernacle shall be put to death. ⁵² The Israelites shall camp according to their armies, every man by his own camp and every man by his own [tribal] standard (banner). ⁵³ But the Levites shall camp around the tabernacle of the Testimony, so that there will be no wrath against the congregation of the Israelites. The Levites shall be in charge of the tabernacle of the Testimony.”