Deuteronomy 2:9

The Moabites, being the descendants of Lot , and so allied by race to the Israelites, the latter were commanded to pass through their country without offering them any injury or assault. Ar, a border-town of Moab ( Numbers 21:15 ), here put for the country itself. It is the Areopolis of the Greeks, and was, as Jerome tells us, destroyed in a single night by an earthquake. A hill with ruins a short distance southwest from Ara'ir, is supposed to be its site.