Kirjathaim - This city, according to Eusebius, was nine miles distant from Medeba, towards the east. It passed from the Emim to the Moabites, from the Moabites to the Amorites, and from the Amorites to the Israelites, Genesis 14:6; Deuteronomy 2:20. Calmet supposes the Reubenites possessed it till the time they were carried away by the Assyrians; and then the Moabites appear to have taken possession of it anew, as he collects from Jeremiah 48:1 etc., and Ezekiel 25:9 etc.
Sibmah - A place remarkable for its vines. See Isaiah 16:8, Isaiah 16:9, Jeremiah 48:32.
Zareth-shahar, in the mount of the valley - This probably means a town situated on or near to a hill in some flat country.

And Kirjathaim,.... Of which See Gill on Numbers 32:37,
and Sibmah; of which See Gill on Numbers 32:3 and See Gill on Numbers 32:38,
and Zarethshahar, in the mount of the valley; which was built on one of the mountains that looked over the valley of Moab, as did Nebo, Pisgah, Abarim; perhaps it is the same place Josephus (k) calls Zara, to which he joins the valley of the Cilicians, and mentions it along with Heshbon, Medeba, and other cities of Moab; according to Adrichomius (l), it was in the mount of the valley of Bethpeor, which next follows.
(k) Antiqu. l. 13. c. 15. sect. 4. (l) Ut supra, (Theatrum Ter. Sanct.) p. 130.

Kirjathaim, where Chedorlaomer defeated the Emim, is probably to be found in the ruins of et-Teym, half an hour to the west of Medaba (see at Genesis 14:5). Sibmah (Numbers 32:38), according to Jerome (on Isaiah 16:8), only 500 paces from Heshbon, appears to have hopelessly disappeared. Zereth-hashachar, i.e., splendor aurorae, which is only mentioned here, was situated "upon a mountain of the valley." According to Joshua 13:27, the valley was the Jordan valley, or rather (according to Genesis 14:3, Genesis 14:8) the vale of Siddim, a valley running down on the eastern side of the Dead Sea. Seetzen conjectures that the town referred to is the present ruin of Sar, on the south of Zerka Maein. - Beth-peor, opposite to Jericho, six Roman miles higher than (to the east of) Libias: see at Numbers 23:28. The "slopes of Pisgah" (Joshua 12:3; Deuteronomy 3:17): to the south of the former, on the north-eastern shore of the Dead Sea (see at Numbers 27:12). Beth-jeshimoth (Joshua 12:3), in the Ghor el Seisabn, on the north-east side of the Dead Sea (see at Numbers 22:1). In Joshua 13:21, the places which Reuben received in addition to those mentioned by name are all summed up in the words, "and all the (other) towns of the plain, and all the kingdom of Sihon," sc., so far as it extended over the plain. These limitations of the words are implied in the context: the first in the fact that towns in the plain are mentioned in Joshua 13:17; the second in the fact that, according to Joshua 13:27, "the rest of the kingdom of Sihon," i.e., the northern portion of it, was given to the Gadites. The allusion to Sihon induced the author to mention his defeat again; see at Numbers 31, where the five Midianitish vassals who were slain with Sihon are noticed in Numbers 31:8, and the death of Balaam is also mentioned. "Dukes of Sihon," properly vassals of Sihon; נסיכים does not signify anointed, however, but means literally poured out, i.e., cast, moulded, enfeoffed. The word points to the "creation of a prince by the communication or pouring in of power" (Gusset, s. v.).

In the mount of the valley - In the mountain bordering upon that valley, which then was famous among the Israelites; whether that where Moses was buried, which was near to Beth - peor, Deuteronomy 34:1, Deuteronomy 34:6, or some other. And this clause is thought to belong to all the cities now mentioned.