John Calvin Commentary Joshua 21:4

"And the lot came out for the families of the Kohathites: and the children of Aaron the priest, who were of the Levites, had by lot out of the tribe of Judah, and out of the tribe of the Simeonites, and out of the tribe of Benjamin, thirteen cities." — Joshua 21:4 (ASV)

And the lot came out for the families...

1. The number of cities is described, which we will discuss later.
2. It is clearly stated that the lot fell to the descendants of Aaron in the tribe of Judah. This did not happen by chance, because God, in His admirable counsel, placed them in that location where He had determined to choose a temple for Himself.
3. The narrative proceeds to give the exact names of the cities. The first one mentioned is Hebron, which Caleb, with great equanimity, allowed himself to be deprived of. If anyone objects that the very first city that should have been given to them was Jerusalem, where they were to have their future station, it is easy to answer that moderate-sized cities were given to them as their condition required.

Moreover, Jerusalem was not yet conquered at that time, as it remained under the power of the Jebusites. In short, it would have been absurd to assign a royal seat to priests. Their religion and faith were better proven by this: that they migrated willingly from their native soil to devote their attention to sacred things.

For no priest performed his duties without becoming a stranger. Their weakness, however, was accommodated to some extent by giving them a grant of neighboring cities, so that they might not have the fatigue of a long journey when going to perform their duties.

Furthermore, the granting of thirteen cities for a dwelling to one family—and that not a very numerous one—confirms what I have said elsewhere: that the other tribes possessed very many cities of which no mention is made. This will be more certainly confirmed in a short time.