Ar'oer (Heb. Aroer', עֲרוֹעֵר [once עִרעוֹר, Jg 11:26], ruins, as in Jer 48:6, "heath;" Sept. Α᾿ρωήρ and Α᾿ροήρ), the name of three places. In Isa 17:2, "cities of Aroer" are mentioned; which some think should be translated " ruined cities," as Aroer was not a metropolis, but the name probably stands as a representative of the two towns in that region.
1. A town "by the brink," or "on the bank of" (both the same expression-- Heb. "on the lip"), or "'by," i.e. on the north side of the torrent Arnon (De 4:48; Jg 11:26; 2Ki 10:33; 1Ch 5:8), and therefore on the southern border of the territory conquered from Sihon, which was assigned to the tribes of Reuben and Gad (De 2:36; De 3:12; Jos 12:2; Jos 13:9). The Amorites had previously dispossessed the Ammonites of this territory; and although the town seems to be given to Reuben (Jos 13:16), it is mentioned as a Moabitish city by Jeremiah (Jer 48:19). According to Eusebius (Onomast. s.v. Α᾿ροήρ) it stood " on the brow of the hill." Burckhardt (comp. Macmichael, Journey, p. 242) found the ruins of this town, under the name of Araayr, on the edge of a precipice overlooking Wady Mojeb (Travels in Syria, p. 372). They are also mentioned under the name Arar in Robinson's Researches (App. to vol. iii, p. 170, and Map). Schwarz places it 15 miles from the Dead Sea (Palest. p. 226). Aroer is always named in conjunction with " the city that is in the midst of the river;" whence Dr. Mansford (Script. Gaz.) conjectures that, like Rabbath Ammon (q.v.), it consisted of two parts, or distinct cities; the one on the bank of the river, and the other in the valley beneath, surrounded, either naturally or artificially, by the waters of the river. For another explanation, SEE ARNON.
2. One of the towns "built," or probably rebuilt, by the tribe of Gad (Nu 32:34). It is said in Jos 13:25, to be "before (עִלאּפּנֵי) Rabbah" [of Ammon]; but, as Raumer well remarks (Palistina, p. 249), this could not possibly have been in the topographical sense of the words (in which before means east of), seeing that Aroer, as a town on the eastern border of Gad, must have been west of Rabbah; while to a person in Palestine proper, or coming from the Jordan, Aroer would be before Rabbah in the ordinary sense. It is (see Ritter, Erdk. 15:1130) apparently the place discovered by Burckhardt (Syria, p. 335), who, in journeying toward Rabbath Ammon, notices a ruined site, called Ayra, about seven miles south-west from es-Salt; probably the same with the Array el-Emir visited by Legh (p. 246) on his way from Heshbon to es-Salt (comp. Schwarz, Palest. p. 231). It is also called Aireh in Robinson's Researches (iii, App. p. 169). Aroer of Gad is also mentioned in Jg 11:33, and 2Sa 24:5, in which latter passage it is stated to have been situated on the ' river" (brook) of Gad, i.e. apparently on the Wady Nimrin (and not the Arnon, see Reland, Palsest. p. 533). Keil (Comment. on Joshua p. 339), approved by Van de Velde (Memoir, p. 288), fixes upon Kulat Zeska Gadda, as lying in a wady and east of Rabbah; but the passage in 2 Samuel (" and they passed over Jordan, and pitched in Aroer, on the right side of the city, that lieth in the midst of the river of Gad. and toward Jazer") can only signify [if, indeed, the word אֲשֶׁר, which, do not signify here merely "to wit," or rather be not altogether spurious] that the party of Joab encamped just across the Jordan, in the bed of one of the brooks of Gad (the Wady Nimrin), south of Aroer and not far from Jaazer. Jerome speaks of it as Aruir (Euseb. Α᾿ρουεί), a village still found on a hill 20 Roman miles south of Jerusalem (Onomast. s.v.); but this, if correct, can only mean south-east.
3. A city in the south of Judah (i.e. in Simeon), to which David sent presents after recovering the spoil of Ziklag (1Sa 30:26,28). It appears to have been the native city of two of David's warriors (1Ch 11:44). At the distance of twenty geographical miles south by west from Hebron, Dr. Robinson (Researches, ii, 618) came to a broad wady where there are many pits for water, which are called Ararah, and which gave name to the valley. In the valley and on the western hill are evident traces of an ancient village or town, consisting only of foundations of unhewn stones, now much scattered, but yet sufficiently distinct to mark them as foundations. Small fragments of pottery are also everywhere visible. The same identification is proposed by Schwarz, who calls the place "the modern village Arar, two and a half English miles south of Moladah" (Palest. p. 113).