From Aroer, which is by the bank of the river Arnon,.... A city of Moab, which was situated on the bank of the river Arnon, that was on the border of Moab, De 2:36,even unto Mount Sion, which [is] Hermon; the meaning is, that the lands of these two kings conquered by Israel reached from the city Aroer on the river Arnon to Mount Hermon, the one being the southern, the other the northern boundary of them.
Here Hermon has another name Sion, and is to be carefully distinguished from Mount Zion near Jerusalem; it lying in a different country, and being written with a different letter in the Hebrew language.