Numbers 1:50, 53

Put the Levites in charge of the Tabernacle of the Covenant, along with all its furnishings and equipment. They must carry the Tabernacle and all its furnishings as you travel, and they must take care of it and camp around it.

But the Levites will camp around the Tabernacle of the Covenant to protect the community of Israel from the LORD’s anger. The Levites are responsible to stand guard around the Tabernacle.”