Deuteronomy 3:12, 16

“When we took possession of this land, I gave to the tribes of Reuben and Gad the territory beyond Aroer along the Arnon Gorge, plus half of the hill country of Gilead with its towns.

But I also gave part of Gilead to the tribes of Reuben and Gad. The area I gave them extended from the middle of the Arnon Gorge in the south to the Jabbok River on the Ammonite frontier.