Aroer was in the border of Moab, but now in the hands of the Amorites. By the river, Heb. in the river, wherewith it was encompassed, Numbers 21:15,28 Jos 12:2 13:9. He speaks exclusively, for this was Ar, which now was in the Moabites jurisdiction, above, Deuteronomy 2:9.
Related Commentaries of Deuteronomy 2:36
Deuteronomy 2:36
36 From Aroer, which is by the brink of the river of Arnon, and from the city that is by the river, even unto Gilead, there was not one city too strong for us: the LORD our God delivered all unto us: