Joshua 1:14-15

1:14 Your wives, children and cattle may stay in the land that Moses assigned to you east of the Jordan River. But all you warriors must cross over armed for battle ahead of your brothers. You must help them 1:15 until the Lord gives your brothers a place like yours to settle and they conquer the land the Lord your God is ready to hand over to them. Then you may go back to your allotted land and occupy the land Moses the Lord’s servant assigned you east of the Jordan.”