The sons of Reuben and the sons of Gad had very large herds, and they see that the lands of Jazer and Gilead are good for their livestock. They ask Moses, Eleazar and the chiefs to give them that land and not make them cross the Jordan. Moses answers angrily: will your brothers go to war while you sit here? He reminds them of what their fathers did when the spies came back from Kadesh, and how their discouragement stirred God's anger and the forty years in the wilderness. He warns them that they are a brood of sinful men adding to the Lord's fury against Israel.
They propose a solution: they will build pens for their livestock and cities for their children, but they themselves will go armed ahead of the Israelites until they have brought them to their place, and they will not return to their homes until each Israelite has received his inheritance. They will not claim an inheritance across the Jordan.
Moses agrees on one condition: if they do it, they will be free of guilt before the Lord and Israel, but if not, they will sin against the Lord and their sin will find them out. He gives instructions to Eleazar, Joshua and the heads of the tribes: if the armed men cross over, they will be given Gilead as a possession; if not, they will receive their inheritance among the others in Canaan. Reuben and Gad commit themselves again. Moses gives them the kingdom of Sihon and of Og, and half the tribe of Manasseh also receives part of the land. The chapter ends by naming the cities they rebuilt and the clans of Manasseh that conquered territories in Gilead and Bashan.