the Tribe of Reuben: Bounds of Their Inheritance
Source: TTT
Deuteronomy 3:16, 17
and to the Reubenites and Gadites I gave the territory from Gilead to the Arnon Valley (the middle of the valley was the border) and up to the Jabbok River, the border of the Ammonites. / The Jordan River in the Arabah bordered it from Chinnereth to the Sea of the Arabah (the Salt Sea) with the slopes of Pisgah to the east.
Joshua 13:15–23
This is what Moses had given to the clans of the tribe of Reuben: / The territory from Aroer on the rim of the Arnon Valley, along with the city in the middle of the valley, to the whole plateau beyond Medeba, / to Heshbon and all its cities on the plateau, including Dibon, Bamoth-baal, Beth-baal-meon,