Numbers 31 - This chapter is a triumph for Moses. He won't be able to go into the Promised Land but he will see revenge against the Midianites and especially against the prophet Balaam. This passage will reveal that it was Balaam who instigated the immorality of chapter 25. God has made clear that sin will be judged and Balaam did not escape. Note the way the spoils of war were distributed amongst Israel. And note how the soldiers made a special contribution of their winnings because not one of them was killed during the fight.
Numbers 32 - This chapter reveals why not all the tribes of Israel were eventual residents of the Promised Land. The tribes of Reuben, Gad, and half the tribe of Manasseh decided they wanted to settle in the land east of the Jordan River. Moses was upset with them until they promised to join the rest of the Israelites in the conquering of the land of Canaan. Moses warned them that "sin will find you out" if they went back on their promise.