Refers to the valley region in the Moab territory east of the Dead Sea. It formed the border between Moab and the Amorites.
Numbers 21:13From there they set out and encamped on the other side of the Arnon, which is in the wilderness and extends from the territory of the Amorites. The Arnon is the border between Moab and the Amorites.Numbers 21:14That is why it says in the Book of the Wars of the Lord: “Suphah in Wahab, and the ravines of the ArnonNumbers 21:15and the slopes of the ravines that lead to the settlement of Ar and lie along the border of Moab.”