Today there are four chapters, there is not one New Testament comment in the three chapters of Joshua. Read them as history and Geography and enjoy!
Luke 15 is deceptively simple. Just three parables, the lost sheep, the lost coin, and finally the lost son, the most famous story of redemption of them all.
Joshua 15, more geography: the land of Judah, Caleb occupies Hebron and Debir and a listing of the cities of Judah.
Joshua 16 describes the land that belongs to the half tribe of Manasseh, west of Jordan, and also the land of Ephraim.
Joshua 17 describes in more detail what is named in previous chapter.