John Gill Commentary Joshua 21:13

"And unto the children of Aaron the priest they gave Hebron with its suburbs, the city of refuge for the manslayer, and Libnah with its suburbs," — Joshua 21:13 (ASV)

Thus they gave to the children of Aaron the priest The families of the Kohathites, that part of them which descended from him, and were priests:

Hebron with her suburbs, [to be] a city of refuge for the slayer that had slain a person unawares, and without design; see on (Joshua 20:3Joshua 20:7).

and Libnah with her suburbs a royal city, of which see (Joshua 10:29Joshua 10:30).