Joshua 1:12-15

12But to the Reubenites, the Gadites and the half-tribe of Manasseh, Joshua said, 13“Remember the command that Moses the servant of the Lord gave you after he said, ‘The Lord your God will give you rest by giving you this land.’ 14Your wives, your children and your livestock may stay in the land that Moses gave you east of the Jordan, but all your fighting men, ready for battle, must cross over ahead of your fellow Israelites. You are to help them 15until the Lord gives them rest, as he has done for you, and until they too have taken possession of the land the Lord your God is giving them. After that, you may go back and occupy your own land, which Moses the servant of the Lord gave you east of the Jordan toward the sunrise.”