Deuteronomy 3:12

So at that time we took possession of this land. To the Reubenites and Gadites I gave the land beyond Aroer along the Arnon Valley, and half the hill country of Gilead, along with its cities.

And this land, which we possessed at that time, from Aroer, which is by the river Arnon, and half mount Gilead, and the cities thereof, gave I unto the Reubenites and to the Gadites.