Edom, Idumaea, or Idumea
(red), the name Edom was given to Esau, the firstborn son of Isaac and twin brother of Jacob, when he sold his birthright to the latter for a meal of lentil pottage. The country which the Lord subsequently gave to Esau was hence called “the country of Edom” (Genesis 32:3), and his descendants were called Edomites. Edom was called Mount Seir and Idumea also. Edom was wholly a mountainous country. It embraced the narrow mountainous tract (about 100 miles long by 20 broad) extending along the eastern side of the Arabah from the northern end of the Gulf of Elath to near the southern end of the Dead Sea. The ancient capital of Edom was Bozrah (Buseireh). Sela (Petra) appears to have been the principal stronghold in the days of Amaziah (2 Kings 14:7). Elath and Ezion-geber were the seaports (2 Samuel 8:14; 1 Kings 9:26).
History — Esau’s bitter hatred to his brother Jacob for fraudulently obtaining his blessing appears to have been inherited by his latest posterity. The Edomites peremptorily refused to permit the Israelites to pass through their land (Numbers 20:18-21). For a period of 400 years we hear no more of the Edomites. They were then attacked and defeated by Saul (1 Samuel 14:47) and some forty years later by David (2 Samuel 8:13, 14). In the reign of Jehoshaphat the Edomites attempted to invade Israel but failed (2 Chronicles 20:22). They joined Nebuchadnezzar when that king besieged Jerusalem. For their cruelty at this time they were fearfully denounced by the later prophets (Isaiah 34:5-8; 63:1-4; Jeremiah 49:17). After this they settled in southern Palestine and for more than four centuries continued to prosper. But during the warlike rule of the Maccabees they were again completely subdued, and even forced to conform to Jewish laws and rites, and submit to the government of Jewish prefects. The Edomites were now incorporated with the Jewish nation. They were idolaters (2 Chronicles 25:14-15, 20). Their habits were singular. The Horites, their predecessors in Mount Seir, were, as their name implies, troglodytes, or dwellers in caves, and the Edomites seem to have adopted their dwellings as well as their country. Everywhere we meet with caves and grottos hewn in the soft sandstone strata.
Smith's Bible Names Dictionary (1866)