Numbers 21:31
After the Israelites settled in the Amorite territory,
Numbers 32:33-42
So Moses gave the tribes of Gad, Reuben, and half of the tribe of Manasseh, son of Joseph, the kingdoms of King Sihon of the Amorites and King Og of Bashan. It was the whole land with its cities and its surrounding territory.
Deuteronomy 3:16-17
I assigned the territory from Gilead to the Arnon River to the tribes of Reuben and Gad. The middle of the river was their southern boundary, and their northern boundary was the Jabbok River, part of which formed the Ammonite border.
Joshua 12:1-6
These are the kings of the land that the children of Israel defeated and who's territory they captured. It was on the other side of Jordan toward the rising of the sun, from the Arnon River to Mount Hermon, and all the plain on the east.
Joshua 13:8-12
With whom the Reubenites and the Gadites have received their inheritance, which Moses gave them, beyond Jordan eastward, even as Moses the servant of Jehovah gave them.