Numbers 4:4

This [shall be] the service of the sons of Kohath, in the
tabernacle of the congregation
What follows, ( Numbers 4:4-15 ) ;

[about] the most holy things;
which Aben Ezra interprets only of the ark, which was indeed a most holy thing, and stood in the most holy place; but there were other holy things, in the care of which the service of the Kohathites lay; as the shewbread table, the candlestick, and the altars of incense and burnt offering, and the vail, and the ministering: vessels, which Jarchi reckons with it, as more holy than all other things.