John Gill Commentary 1 Chronicles 15:4

"And David gathered together the sons of Aaron, and the Levites:" — 1 Chronicles 15:4 (ASV)

Ver. 4-10. And David assembled the children of Aaron, and the
Levites .

] Whose business it was to bear the ark when there was any occasion for it: and from hence to the end of (1 Chronicles 15:10) an account is given of the Levites, and their number employed in this affair:

of the sons of Kohath ; a son of Levi, that is, of his posterity; for his immediate sons, and so those of the rest after mentioned, had been dead ages ago; the principal of those, at this present time, was Uriel, and his kindred, or those of the same family with him, were one hundred and twenty:

of those of Merari, another son of Levi, the chief was Asaiah, with two hundred and twenty of his relations:

of those of Gershon, another son of Levi, was Joel, and his brethren were one hundred and thirty:

of the posterity of Elizaphan, a grandson of Kohath, (Exodus 5:18Exodus 5:22) , the most noted was Shemaiah, who had two hundred of his family with him:

and of those of Hebron, the son of Kohath, (Exodus 6:18) , Eliel was the most famous, and he had eighty of his kindred with him:

and of those of Uzziel, another son of Kohath in a different line from Elizaphan, who also was a son of Uzziel, was Amminadab the chief, who had one hundred and twelve of his kindred with him: the number of Levites, in all, gathered together, were eight hundred and sixty two, besides their chiefs.