Chapters 13 to 21 explain how the land was divided up and settled, and chapters 22 to 24 give Joshua's farewell speeches and the renewal of God's agreement and promises with the children of Israel.
Later editors evidently made a few additions, such as the description of Joshua's death.
"Traditionally, the Old Testament is divided into three sections: the Law, Prophets and Writings (or Psalms, so named from the first book of that section).
There remains therefore a rest [Sabbath-rest, New International Version] for the people of God.
For he who has entered His rest has himself also ceased from his works as God did from His.
And not a man of all their enemies stood against them; the Lord delivered all their enemies into their hand.
Joshua served as a type of Jesus Christ leading His people into a spiritual Promised Land, inheriting the Kingdom of God and overcoming evil along the way.
And to whom did He swear that they would not enter His rest, but to those who did not obey?
So we see that they could not enter in because of unbelief.
"The Hebrew name Joshua or Hebrews -19 For we have become partakers of Christ if we hold the beginning of our confidence steadfast to the end, while it is said: "Today, if you will hear His voice, do not harden your hearts as in the rebellion." For who, having heard, rebelled?
Indeed, was it not all who came out of Egypt, led by Moses? Was it not with those who sinned, whose corpses fell in the wilderness?
Though it may have been written by various authors, adding to the storyline as events transpired—e.g., the Song of Deborah and the parable of Jotham—it was probably put into its final form by the last of the judges, Samuel, in the 11th century B. The Talmud states, 'Samuel wrote the book which bears his name and the book of Judges' 14b).