The book of Joshua is, basically, a book that tells about the covenant. God keeps his covenant. Beginning with the first chapter, the Lord said to Joshua, he reminded him that what Joshua was going to go through was part of the covenant that God had given to his predecessors — to Abraham, to Isaac, to Jacob, and now, to Moses, and now, also, Joshua was the one chosen by God to claim God's promise. And if we continue to read chapter after chapter, the covenant is always repeated by God. In fact, even in chapter 1, the Lord reminded Joshua, commanded Joshua to remind the nation of Israel, not to forget the law of Moses. And we know the law of Moses is part of God's covenant. And then, in chapter 7 — Achan's sin — God said that that sin was not merely an ordinary sin, but it was sin because it violated God's covenant. And then, in chapter 8, Joshua instructed the nation of Israel to remember God's covenant on Mount Ebal, and there he wrote again God's covenant and read it to the whole nation of Israel. In chapters 13–21, which was the division of the land, there was the climax of the fulfillment of that promise — not only the promise of land but, as it turns out, also the promise of offspring from one man, Abraham, now becoming one nation, twelve tribes, and also the promise of land that now was truly given by God to them. Each tribe possessed their own land and they enjoyed the promise that God had given to the nation of Israel. So, the book of Joshua, if we read it from chapter 1 to the last chapter, all of it talks about God's covenant.