John Gill Commentary Joshua 21:20

"And the families of the children of Kohath, the Levites, even the rest of the children of Kohath, they had the cities of their lot out of the tribe of Ephraim." — Joshua 21:20 (ASV)

And the families of the children of Kohath, the Levites
Who were not priests: which remained of the children of Kohath ;
these are the children of Moses, as Jarchi says, and those that descended from Kohath in the lines of Izhar, Hebron, and Uzziel, even they had the cities of their lot out of the tribe of Ephraim ;
and were as follow.