9 from Aroer, that is on the edge of the valley of the Arnon, and the city that is in the middle of the valley, and all the plain of Medeba to Dibon;
*Minor differences ignored. Grouped by changes, with first version listed as example.
From Aroer - See on Joshua 12:2 (note).
From Aroer, that is on the bank of the river Arnon,.... A city belonging to Moab, from whence the description begins, the river Arnon, on which it was situated, being the border between Moab and the Amorites, Numbers 21:13,
and the city that is in the midst of the river; or "even the city"; meaning the same city of Aroer, it lying both on the bank of it, and in the middle of it, or it was a double city, as may seem from Isaiah 17:2; and so differently situated at that river:
and all the plains of Medeba unto Dibon; of these two places, see Numbers 21:30; between them lay a plain, which some take to be the plain of Moab; but it rather seems to be a plain that was between these two places, and, according to Joshua 13:17, Dibon itself was in a plain.
Medeba unto Dibon - Two cities anciently belonging to the Moabites, and taken from them by the Amorites, Numbers 21:30, and from them by the Israelites; and after the Israelites were gone into captivity, recovered by the first possessors, the Moabites.
*More commentary available at chapter level.