THE NATURE OF EDOM.

EDOM is the name of a nation, a geographical region, and a person in Old Testament times. The name,
Edom, is derived from a root word meaning "red, ruddy"and was the secondary name or byname given to Esau, the elder of the twins born to Isaac and Rebekah; the younger was Jacob. (Gen36:1)
The Genesis 25 story of Esau's birth gives 3 clues to his being called "Edom" or "Red." It was applied to him because of his appearance at birth having a very ruddy color ; and then by associating the name with the red stew he got from his brother, Jacob, by selling his birthright to him. And the final clue is that a similar color prevailed in the appearance of the rock and soil formations in parts of the land of Edom that his descendants later inhabited.
Sometime during Jacob's 20-year stay in Haran, Esau (Edom) had begun to establish himself in the land  of Seir, "the field of Edom."(Gen32:3) Thus, even before the death of his father (Gen35:29), Esau began to fulfill Isaac's prophetic blessing, directing his attention away from the fertile soils around Hebron and beginning to "live by his sword," along with the 400 men under his command. (Gen27 : 39,40; 32:6,8) He still maintained residence in the Hebron area, not transferring definitely to the mountainous region of Seir until after his father's death. By then his family has grown and his possessions were great. (Genesis 36: 6-8)
The land of Seir had previously been the domain of Horites (Gen 14:6; 36:20-30), but Esau's sons dispossessed the Horite sheiks and took over the region. (Deut 2:12) Thereafter the land became known as the land of Edom, though the older name of Seir still continued to be in use. (Num 24:18)
Genesis 36 includes a list of kings who ruled the land of Edom before any king ruled over the Israelites. The same chapter lists wives and descendants of Esau as well as some Horite lists.
The Edomites as descendants of Esau were basically a Semitic race, but with a strong Hamitic strain. This was due to Esau and its nature itself and the marriage with 2 wives being from Hamitic Canaanite stock (Hittite and Hivite), only one of all being Semitic, through Abraham's son Ishmael.
At any rate, the Edomites, and Lot's descendants (Moabites and Ammonites) were related to the Israelites and originally they also practiced circumcision (Jeremiah 9; Ezekiel 32). God referred to them as Israel's "brothers"and Edomite land rights were to be held inviolate by the Israelites advancing through the Wilderness," since GOD had granted Edom's descendants Mount Seir as a holding.(Deut2)
According to Number 20 during the wilderness wanderings the "king of Edom" refused to permit the Israelites safe passage through his land, forcing them to circumvent Edom. Moses requested permission for Israel to travel over the King's Road through Edom. This road, called "the King's Highway,"was from the Gulf of Aqabah on up to Damascus in Syria, following the edge of the High Plateaus lining the East Side of the Arabah when traversing Edom. Along the King's Highway were to be found the major cities of Edom, including Bozrah and Petra (connected with Scriptural Sela).
2 Kings 14 says, "In the 2nd year of the reign of Jeho'Ash son of Jeho'Ahaz as king of Israel, Amaz'Iah son of Jo'Ash became king of Judah at the age of 25 and he ruled in Jerusalem for 29 years. His mother was Jeho'Addin from Jerusalem. He did what was pleasing to the Lord, but he was not like his ancestor King David; instead, he did what his father Jo'Ash had done. He did not tear down the pagan places of worship, and the people continued to offer sacrifices and burn incense there. As soon as Amaz'Iah was firmly in power, he executed the officials who had killed his father, the king. However, he did not kill their children but followed what the Lord had commanded in the Law of Moses: "Parents are not to be put to death for crimes committed by their children, and children are not to be put to death for crimes committed by their parents; people are to be put to death only for a crime they themselves have committed."Amaz"iah killed 10,000 Edomite soldiers in Salt Valley; he captured the city of Sela in battle and called it Jokt'Heel, the name it still has."
A "route"also led from the Negeb (Isaiah 30 described it as a land of hard conditions, a haunt of lions, leopards and snakes) over to Petra, continued East through Ma'An on the edge of the Arabian Desert, connecting there with another "route" running North and South. Over "these roads" passed rich cargoes from Egypt, Arabia, Syria, and Mesopotamia. Toll collected from camel or donkey caravans traversing the roads likely contributed greatly to Edom's wealth. Weary desert travelers also paid for food and lodging upon reaching Edom. Petra became a rich trading city, rivaling Damascus in importance.
The "steep escarpment" or wall of the Plateau that faced the Arabah gave the main stronghold of Edom excellent protection from that direction. The "deep canyon" of Zered Valley impeded invasion from Moab (however Amos 2 says:"They dishonored the bones of the king of Edom by burning them to ashes"). A "chain of fortresses" faced the desert to the more vulnerable East, providing defense against Midianite and other tribes. Additionally the "clefts"that cut into the mountains and Plateaus are walled in by unscalable "red sandstone cliffs"forming forbidding gorges. With good reason GOD's prophecy through Jeremiah speaks of the "Edomites" as confidently "residing in the retreats of the crag, holding the height of the hill," and like "an eagle in its nest." (Jeremiah 49).
The prophets Joel and Amos pronounced GOD's positive condemnation of Edom for its "unrelenting fury" expressed against Israel by the unmerciful use of the sword. Edom by its vicious opposition to GOD's covenant people, had forfeited its right to the land it had held by Divine Warrant.
The Edomites sealed their doom when Babylonians conquered Judah and Jerusalem and their hatred was clearly revealed as they rejoiced at Judah's tragedy, urged on her devastators (Ps 137:7), and, in their enmity and desire for revenge, even turned over Judean escapees for slaughter by the Babylonians.
They joined other neighboring peoples in plundering the land, and planned to take over the abandoned country of Judah and of Israel, speaking boastfully against GOD. For this, GOD directed His Prophets
Jeremiah, Ezekiel, and Obadiah to assure Edom that "its rejoicing" would be short-lived.
As the Prophet Isaiah had earlier foretold, the sword-welding Edomites would come under GOD's own Sword of Justice and Judgment, all classes, great and small, becoming like sacrificial animals devoted to destruction (Isaiah 34).