The people of Edom lived just south of the Dead Sea, below Israel and, later, Judah. They spoke a Canaanite language similar to Hebrew. The geographical closeness between Edom and Israel and Judah means that Edom appears with some frequency in the Old Testament. The Old Testament authors understood the Edomites to be the descendants of Esau, which meant that this people possessed a close connection to the Israelites.
The relationship between Esau and Edom is reinforced in the Bible through numerous examples of wordplay. “Edom” sounds like the Hebrew word for red. Genesis 25:30 derives the name Edom from Esau’s sale of his birthright for a bowl of soup made from red lentils. The capital of Edom was Mount Seir, which sounds like the Hebrew word for hairy. When Esau was born, he came out red and hairy, thus connecting him to both Mount Seir and Edom.
Mentions of Edom continue throughout scripture—for example, King Saul’s chief herdsman, Doeg, was an Edomite. And according to 2 Samuel 8:14–15, David exerted military control over Edom, which caused difficulties during Solomon’s reign (see 1 Kings 11:14–15). Outside of the Old Testament period, the Hasmoneans forcibly converted the Edomites (called Idumeans in Greek) to Judaism. King Herod from the first chapters of the Gospel of Matthew was descended from these converts. Edom became associated with Rome in later Jewish literature, and Idumea (Edom) was used as a symbol for the world as opposed to the Church in Doctrine and Covenants 1:36.