Before the Tribe of Israel crosses into the Promised Land, Moses begins to recount their journey out of Egypt, the laws they have been given, the failings of the tribe, observing commandments, and events from the last 40 years of their journey.
Moses recounts appointing leaders of thousands, hundreds, and tens – judges and magistrates to ease his burden and to help teach the word of G-d. The spies sent to see the Promised land, the rejection of the land by the people, and the consequence of the entire generation not living to cross into that land.
Moses tells of how Moab and Ammon would not let the Israelites through their land and the wars with the Emorite kings Og and Sichon. That land conquered would be settled by the tribes of Reuben, Gad, and Manasseh.
Given their challenges, knowing Moses will not enter the Promised Land, he gave a message to Joshua who will take over as their leader not to fear them because G-d will fight for him.