Open the side of Moab — i.e., lay it open to the enemy. This is to be done “from the cities,” on which a special emphasis is placed. The cities named were all on the north of the Arnon, and before the time of Moses had been wrested from the Moabites by the Amorites, from whom in turn they were taken by the Israelites, and long formed a part of their territory. In the decay of the power of Israel they were re-conquered by Moab, and are here spoken of, perhaps in view of their being rightfully a possession of Israel, as appropriately the point from which desolation should go out over the whole of Moab.
The glory of the country. — The territory designated by the mention of these three cities is still considered by the Arabs as the best part of the land, and is called Belka. They have a proverb, “Thou canst find no land like Belka.” The sites of all the cities which are alluded to here have been probably identified by existing ruins.