Numbers 1:50

The tabernacle of testimony. — The testimony (sometimes described as the two tables of the testimony (Exodus 31:18; Exodus 34:29) denotes in the first instance the tables of the law which were directed to be placed in the ark (Exodus 25:16; Exodus 25:21). Hence the ark is described as the ark of the testimony (Exodus 25:22; Exodus 26:33), and the tabernacle as the tabernacle of the testimony (Exodus 38:21), and the tent, including the outer covering of the mishkan, or wooden building, is called the tent of the testimony (Numbers 9:15). Also the veil which separated the holy place from the most holy is called the veil of the testimony (Leviticus 24:3).

And shall encamp round about the tabernacle. — The tent of meeting was like a royal palace, and the Levites served as a guard of honour round about it, to protect it from every sort of desecration.