Edom

Idumea—originally extending from the Dead Sea to the Red Sea; afterwards the Idumeans obtained possession of the country east of Moab, of which Bozrah was capital. Petra, or Selah, called Joktheel by Amaziah, who took it (2 Ki. 14:7), was capital of South Edom (note, ch. 16:1). David subjugated Edom (2 Sam. 8:13, 14). Under Jehoram they regained independence (2 Chr. 21:8). Under Amaziah they were again subdued, and Selah taken (2 Ki. 14:7). When Judah was captive in Babylon, Edom, in every way, insulted over her fallen mistress, and killed many of those Jews whom the Chaldeans had left, and hence was held guilty of fratricide by God (Esau, their ancestor, having been brother to Jacob). This was the cause of the denunciations of the prophets against Edom (ch. 63:1, &c.; Jer. 49:7; Ezek. 25:12–14; 35:3–15; Joel 3:19; Amos 1:11, 12; Obad. 8, 10, 12–18; Mal. 1:3, 4). Nebuchadnezzar humbled Idumea accordingly (Jer. 25:15–21). and upon the people of my curse—i. e., doomed to it. to judgment—i. e., to execute it.

A. R. Fausset, A Commentary, Critical, Experimental, and Practical, on the Old and New Testaments: Job–Isaiah, vol. III (London; Glasgow: William Collins, Sons, & Company, Limited, n.d.), 667.