Joshua 13:8-10

8With the other half-tribe [of Manasseh], the Reubenites and the Gadites received their inheritance which Moses gave them beyond the Jordan eastward, just as Moses the servant of the Lord gave to them;

9from Aroer on the edge of the valley of the [river] Arnon, and the city in the middle of the valley, and all the plain of Medeba, as far as Dibon;

10and all the cities of Sihon king of the Amorites, who reigned in Heshbon, as far as the border of the Ammonites;