and were in the valley near Beth Peor east of the Jordan, in the land of Sihon king of the Amorites, who reigned in Heshbon and was defeated by Moses and the Israelites as they came out of Egypt.
References for Deuteronomy 4:46
They took possession of his land and the land of Og king of Bashan, the two Amorite kings east of the Jordan.
This land extended from Aroer on the rim of the Arnon Gorge to Mount Sirion (that is, Hermon),
References for Deuteronomy 4:48