Albert Barnes Commentary 2 Kings 8:21

"Then Joram passed over to Zair, and all his chariots with him: and he rose up by night, and smote the Edomites that compassed him about, and the captains of the chariots; and the people fled to their tents." — 2 Kings 8:21 (ASV)

Zair - Perhaps this refers to Seir, the famous mountain of Edom (Genesis 14:6).

The people - That is, the Edomites. Yet, despite his success, Joram was forced to withdraw from the country and leave the natives to enjoy their independence (2 Kings 8:22), which continued until the time of John Hyrcanus, who subdued them once more.