John Gill Bible Commentary

And the Kohathites set forward,.... After the standard of the camps of Reuben, and between that and the standard of the camp of Ephraim, to, which there is an allusion in Psa 80:2, bearing the sanctuary, or the holy things, as Jarchi; the ark, as Aben Ezra; though not that only, which indeed might be eminently called so, it standing in the most holy place, over which were the mercy seat and cherubim, the residence of the divine Majesty; but all the holy things in the holy place, the candlestick, shewbread table, and the two altars, the altar of incense in the holy place, and the altar of burnt offerings in the court these they bore on their shoulders, and had no wagons allowed for their assistance: and the other did set up the tabernacle against they came; that is, the sons of Gershon and Merari, who went before between the standard of Judah and the standard of Reuben, carrying the heavier and more cumbersome parts of the tabernacle; which, when Judah pitched their tents, at the signal of the cloud, they immediately put together, and erected, and got it ready, by such time as the Kohathites came up to them, that so the ark and other holy things might be at once put into it, and set in their proper places.