Deuteronomy 3:8

At that time we took their land from the two kings of the Amorites on the far side of Jordan, from the valley of the Arnon to Mount Hermon;

Joshua 12:2-6

Sihon, king of the Amorites, who was living in Heshbon, ruling from Aroer, which is on the edge of the valley of the Arnon, and the town in the middle of the valley, and half Gilead, as far as the river Jabbok, the limits of the children of Ammon;

Joshua 13:9-12

From Aroer, on the edge of the valley of the Arnon, and the town in the middle of the valley, and all the table-land from Medeba to Dibon;

Numbers 32:33-42

So Moses gave to them, even to the children of Gad and the children of Reuben and to the half-tribe of Manasseh, the son of Joseph, the kingdom of Sihon, king of the Amorites and Og, king of Bashan, all the land with its towns and the country round them.

Treasury of Scripture Knowledge

Summary

And we took at that time out of the hand of the two kings of the Amorites the land that was on this side Jordan, from the river of Arnon unto mount Hermon;

Bible References

The land

Numbers 32:33
So Moses gave to them, even to the children of Gad and the children of Reuben and to the half-tribe of Manasseh, the son of Joseph, the kingdom of Sihon, king of the Amorites and Og, king of Bashan, all the land with its towns and the country round them.
Joshua 12:2
Sihon, king of the Amorites, who was living in Heshbon, ruling from Aroer, which is on the edge of the valley of the Arnon, and the town in the middle of the valley, and half Gilead, as far as the river Jabbok, the limits of the children of Ammon;
Joshua 13:9
From Aroer, on the edge of the valley of the Arnon, and the town in the middle of the valley, and all the table-land from Medeba to Dibon;

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain