2:8-23 We have the origin of the Moabites, Edomites, and Ammonites. Moses also gives an instance older than any of these; the Caphtorims drove the Avims out of their country. These revolutions show what uncertain things wordly possessions are. It was so of old, and ever will be so. Families decline, and from them estates are transferred to families that increase; so little continuance is there in these things. This is recorded to encourage the children of Israel. If the providence of God has done this for Moabites and Ammonites, much more would his promise do it for Israel, his peculiar people. Cautions are given not to meddle with Moabites and Ammonites. Even wicked men must not be wronged. God gives and preserves outward blessings to wicked men; these are not the best things, he has better in store for his own children.
8-18. we passed … through the way of the plain—the Arabah or great valley, from Elath ("trees") (the Ailah of the Greeks and Romans). The site of it is marked by extensive mounds of rubbish.
Ezion-geber—now Akaba, both were within the territory of Edom; and after making a circuit of its southeastern boundary, the Israelites reached the border of Moab on the southeast of the Salt Sea. They had been forbidden by divine command to molest the Moabites in any way; and this special honor was conferred on that people not on their own account, for they were very wicked, but in virtue of their descent from Lot. (See on De 23:3). Their territory comprised the fine country on the south, and partly on the north of the Arnon. They had won it by their arms from the original inhabitants, the Emims, a race, terrible, as their name imports, for physical power and stature (Ge 14:5), in like manner as the Edomites had obtained their settlement by the overthrow of the original occupiers of Seir, the Horims (Ge 14:6), who were troglodytes, or dwellers in caves. Moses alluded to these circumstances to encourage his countrymen to believe that God would much more enable them to expel the wicked and accursed Canaanites. At that time, however, the Moabites, having lost the greater part of their possessions through the usurpations of Sihon, were reduced to the small but fertile region between the Zered and the Arnon.