Deuteronomy 3:16-20

3:16 To the Reubenites and Gadites I allocated the territory extending from Gilead as far as Wadi Arnon (the exact middle of the wadi was a boundary) all the way to the Wadi Jabbok, the Ammonite border. 3:17 The Arabah and the Jordan River were also a border, from the sea of Chinnereth to the sea of the Arabah (that is, the Salt Sea), beneath the watershed of Pisgah to the east.

Instructions to the Transjordanian Tribes

3:18 At that time I instructed you as follows: “The Lord your God has given you this land for your possession. You warriors are to cross over before your fellow Israelites equipped for battle. 3:19 But your wives, children, and livestock (of which I know you have many) may remain in the cities I have given you. 3:20 You must fight until the Lord gives your countrymen victory as he did you and they take possession of the land that the Lord your God is giving them on the other side of the Jordan River. Then each of you may return to his own territory that I have given you.”