The cities here named fall into three groups. On Dibon, compare Numbers 21:19. The Moabite stone was discovered here in 1868. This city, occupied on the first acquisition of the territory by the Gadites, and assigned by Joshua to the Reubenites, was eventually recaptured by the Moabites, in whose hands it remained. Ataroth, i. e., "crowns" (Attarus?) was seven miles northwest of Dibon. Aroer (Arair) lay between Dibon and the Arnon.
Atroth, Shophan - , was Atroth-Shophan, i. e., Atroth, or Ataroth of Shophan, or "of the burrow;" thus distinguished from the Ataroth named in the verse preceding from which it was probably not far distant. These four cities may be styled the Dibon settlement.

The children of Gad built - Aroer - This was situated on the river Arnon, Deuteronomy 2:36; 2-Kings 10:33. It was formerly inhabited by the Emim, a warlike and perhaps gigantic people. They were expelled by the Moabites; the Moabites by the Amorites; and the Amorites by the Israelites. The Gadites then possessed it till the captivity of their tribe, with that of Reuben and the half of the tribe of Manasseh, by the Assyrians, 2-Kings 15:29, after which the Moabites appear to have repossessed it, as they seem to have occupied it in the days of Jeremiah, Jeremiah 48:15-20.

And the children of Gad built,.... Or rather repaired the walls and fortifications, and rebuilt houses which had been demolished in the wars with Sihon and Og; when the following places were taken by the Israelites:
Dibon, and Ataroth, and Aroer; the two first are mentioned in Numbers 32:3. Aroer was a city situated on the river Arnon, and was after this in the hands of the Moabites: Jerom says (q), it was showed in his day on the top of the mountain, upon the bank of the river Arnon, which flows into the Dead sea, Jeremiah 48:19.
(q) De loc. Hebrews. fol. 87. I.

And the children of Gad built--(See on Numbers 32:16).
Dibon--identified with Dheban, now in ruins, an hour's distance from the Arnon (Mojeb).
Ataroth (Hebrew, "crowns")--There are several towns so called in Scripture, but this one in the tribe of Gad has not been identified.
Aroer--now Arair, standing on a precipice on the north bank of the Arnon.

The Gadites built, i.e., restored and fortified, the following places. Dibon, also called Dibon Gad, an hour's journey to the north of the central Arnon. Ataroth, probably preserved in the extensive ruins of Attarus, on Jebel Attarus, between el Krriath (Kureyat) and Makur, i.e., Machaerus (see Seetzen, ii. p. 342). Aroer, not the Aroer before Rabbah, which was allotted to the Gadites (Joshua 13:25), as v. Raumer supposes; but the Aroer of Reuben in the centre of the valley of the Arnon (Joshua 12:2; Joshua 13:9, Joshua 13:16), which is still to be seen in the ruins of Araayr, on the edge of the lofty rocky wall which bounds the Modjeb (Burckhardt, p. 633). Atroth Shophan: only mentioned here; situation unknown. Jaezer: probably to be sought for in the ruins of es Szir, to the west of Ammn (see at Numbers 21:32). Jogbehah: only mentioned again in Judges 8:11, and preserved in the ruins of Jebeiha, about two hours to the north-west of Ammn (Burckhardt, p. 618; Robinson, App. p. 168). Beth-nimrah, contracted into Nimrah (Numbers 32:3), according to Joshua 13:27, in the valley of the Jordan, and according to the Onomast. (s. v. Βηθναβράν) Beth-amnaram, five Roman miles to the north of Libias (Bethharam), now to be seen in the ruins of Nimrein or Nemrin, where the Wady Shaib enters the Jordan (Burckhardt, pp. 609, 661; Robinson, ii. p. 279), in a site abounding in water and pasturage (Seetzen, ii. pp. 318, 716). Beth-Haran, or Beth-Haram (Joshua 13:27): Beth-ramphtha, according to Josephus, Ant. 18:2, 1, which was called Julias, in honour of the wife of Augustus. According to the Onomast. it was called Beth-Ramtha by the Syrians (רמתא בּית, the form of the Aramaean stat. emphat.), and was named Livias by Herod Antipas, in honour of Livia, the wife of Augustus. It has been preserved in the ruins of Rameh, not far from the mouth of the Wady Hesbn (Burckhardt, p. 661, and Robinson, ii. 305). The words וגו מבצר ערי in Numbers 32:36 are governed by ויּבנוּ in Numbers 32:34 : "they built them as fortified cities and folds for flocks," i.e., they fortified them, and built folds in them.

Built - Repaired and fortified. For they neither had need nor leisure as yet to do more, the old cities not being burnt and ruined, as divers in Canaan were.