|Easton's Bible Dictionary|
House of the desert, one of the six cities of Judah, situated in the sunk valley of the Jordan and Dead Sea (Joshua 18:22). In Joshua 15:61 it is said to have been "in the wilderness." It was afterwards included in the towns of Benjamin. It is called Arabah (Joshua 18:18).
Int. Standard Bible Encyclopedia
beth-ar'-a-ba (beth ha-`arabhah; Baitharaba, "place of the Arabah"):
(1) One of the 6 cities of Judah "in the wilderness" (Joshua 15:61), on the borders of Benjamin and Judah (Joshua 15:6; Joshua 18:18 Septuagint). "The wilderness of Judah" is the barren land West of the Dead Sea. Beth-arabah is not yet identified.
(2) One of the cities of Benjamin (Joshua 18:22). Septuagint (Codex Vaticanus) reads Baithabara, and this may be correct. The names are early confounded.
Betharabah (3 Occurrences)
Joshua 15:6 And the border went up to Bethhogla, and passed along by the north of Betharabah; and the border went up to the stone of Bohan the son of Reuben: (KJV)
Joshua 15:61 In the wilderness, Betharabah, Middin, and Secacah, (KJV)
Joshua 18:22 And Betharabah, and Zemaraim, and Bethel, (KJV)