10 which were for the children of Aaron, one of the families of the Kohathites, who were of the children of Levi; for the lot was theirs first. 11 And they gave them Kirjath Arba (Arba was the father of Anak), which is Hebron, in the mountains of Judah, with the common-land surrounding it. 12 But the fields of the city and its villages they gave to Caleb the son of Jephunneh as his possession.
Matthew Henry's Commentary on Joshua 21:10-12
Commentary on Joshua 21:9-42
(Read Joshua 21:9-42)
By mixing the Levites with the other tribes, they were made to see that the eyes of all Israel were upon them, and therefore it was their concern to walk so that their ministry might not be blamed. Every tribe had its share of Levites' cities. Thus did God graciously provide for keeping up religion among them, and that they might have the word in all parts of the land. Yet, blessed be God, we have the gospel more diffused amongst us.