Joshua 1:13-14

“Remember the word which Moses the servant of the LORD commanded you, saying, ‘The LORD your God is giving you rest (peace) and will give you this land [east of the Jordan].’ Your wives, your children, and your cattle shall [be allowed to] stay in the land which Moses gave you on this [eastern] side of the Jordan, but you shall go across [the river] before your brothers (the other tribes) armed for battle, all your brave warriors, and you shall help them [conquer and take possession of their land]