Joshua summoned the Reubenites, the Gadites, and the half-tribe of Manasseh and commended them for obeying God, Moses, and him in taking the land from the Canaanites alongside of their brethren. He then released them to return to their land East of the Jordan. His only instruction was to obey all that the Lord had commanded. So they returned to their territory and lived in the blessings of the Lord.
The thought of this story can be summed up by thinking of the selflessness and faithfulness of family. Brothers should stand shoulder to shoulder and fight the enemy together. Do not give up on your brothers and sisters in the Lord, either. God is looking for faithfulness. When you stand with your brothers and sisters, God will stand with you and provide for your needs.