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.