Charles Ellicott Commentary Jeremiah 48:19

"O inhabitant of Aroer, stand by the way, and watch: ask him that fleeth, and her that escapeth; say, What hath been done?" — Jeremiah 48:19 (ASV)

O inhabitant of Aroer. —There seem to have been two cities of this name: one which had belonged first to the territory of Sihon, then to Reuben, then to Moab, on the north side of the Arnon (Deuteronomy 2:36; Deuteronomy 3:12; Deuteronomy 4:48; Joshua 12:2); another in the Ammonite territory belonging to Gad, near Rabbath-Ammon, in the valley of the Jabbok (Numbers 32:34; Joshua 13:25; Judges 11:33).

Both are probably comprised under the “cities of Aroer” in Isaiah 17:2. The name exists in the modern Arair.

As lying on the frontier, the inhabitants of the Northern Aroer are represented as seeing the fugitives, male and female, from Dibon, and asking what had happened to drive them from their city.

Milton’s lines (Paradise Lost, Book I, line 407) may be quoted as illustrating the topography:

“From Aroer to Nebo, and the wild
Of Southmost Abarim; in Hesebon
And Horonaim, Seon’s realm ...”