Chapter thirteen begins the second half of the book, which details the parceling out and settling of the land of Canaan by the remaining “nine tribes and the half-tribe of Manasseh” (Joshua 13:7). Joshua 13:1 notes that Joshua was very old, but we do not know exactly what that means. According to Joshua 24:29 he was 110 years old when he died, when “a long time passed after the LORD made Israel secure from their enemies” (Joshua 23:1), and Joshua acknowledged that he was very old. How many years are between chapters 13 and 23 is unknown.
As mentioned in the chapter twelve notes, God said that “a great deal of land remain[ed] to be conquered.” Joshua’s job was to lead the nation to break the strongholds of the nations over the land of Canaan. Once the land was parceled out to the tribes, they would be responsible for clearing the remainder of the peoples from their land. The next several chapters (13-19) lay out the borders of the various tribes. The key is to notice that the borders were assigned to the tribes. There was going to be no fighting for land. God had given them the land as a nation, and God divided it out to them through Moses (east of Jordan) and Joshua (west of Jordan).
Sadly, Israel’s downfall that would plague them for centuries was already evident here. Speaking of the two-and-a-half eastern tribes, “But the Israelites did not conquer the Geshurites and Maacathites; Geshur and Maacah live among Israel to this very day” (when this was written; Joshua 13:13). The book of Judges will show the devastation that occurred because of the peoples that Israel allowed to remain in the land.
Another point of interest is that the tribe of Levi would not receive any land. Chapter 20 will deal with the Levitical cities, but, because they were the priests of God among the people, “their inheritance [was] the sacrificial offerings” (Joshua 13:14). In other words, the Levites lived off of the sacrifices and offerings given by the other tribes. More specifically, “their inheritance [was] the LORD God of Israel” himself, as they served him (Joshua 13:33).