Joshua 21:1–42 describes the allocation of forty-eight cities from the territories of the other tribes for the Levites. The cities would serve as places where the Levites could live and keep some livestock. They were apportioned by lot and divided between the descendants of Kohath, Gershon, and Merari. On average, each of the tribes gave four cities, however, when it came to Judah and Simeon they gave nine in order to make up for Naphtali who gave only three cities (Joshua 21:32).
The list in Joshua 21:1–42 follows a very clear and well-thought-out structure:1
1. Introduction (Joshua 21:1–8)
a. Preface (Joshua 21:1–3)
b. Kohathites: twenty-three cities (Joshua 21:4–5)
c. Gershonites: thirteen cities (Joshua 21:6)
d. Merarites: twelve cities (Joshua 21:7)
e. Synopsis (Joshua 21:8)
2. Kohathites’ cities (Joshua 21:9–26)
a. Aaron’s priestly descendants: thirteen cities (Joshua 21:9–19)
b. Rest of the Kohathites: ten cities (Joshua 21:20–26)
3. Gershonites’ cities: thirteen cities (Joshua 21:27–33)
4. Merarites’s cities: twelve cities (Joshua 21:34–40)
5. Total: forty-eight cities (Joshua 21:41–42)
In the context of Joshua, the allocation and purpose of these cities are mentioned in order to confirm that the people of Israel are doing what the Lord commanded them to do.
1 Then the heads of the fathers’ houses of the Levites came to Eleazar the priest and to Joshua the son of Nun and to the heads of the fathers’ houses of the tribes of the people of Israel.