John Wesley on Joshua 21:4

Judah, Simeon, and Benjamin - Which three tribes were nearest the temple, where their business lay. Thirteen cities - For though the priests were now few enough for one city, yet respect was to be had to their succeeding numbers; this division being made for all future generations. And seeing the Levites might sell their houses until the Jubilee, Lev 25:33, much more might they let them; and therefore it is probable their cities were not long uninhabited, many being inclined to dwell with them by virtue of relations contracted with them; or out of respect to the service of God, and the good of their souls.