20 In his days Edom revolted from the rule of Judah, and set up a king of their own. 21 Then Joram passed over to Za'ir with all his chariots, and rose by night, and he and his chariot commanders smote the E'domites who had surrounded him; but his army fled home. 22 So Edom revolted from the rule of Judah to this day. Then Libnah revolted at the same time.
Matthew Henry's Commentary on 2 Kings 8:20-22
Commentary on 2 Kings 8:16-24
(Read 2 Kings 8:16-24)
A general idea is given of Jehoram's badness. His father, no doubt, had him taught the true knowledge of the Lord, but did ill to marry him to the daughter of Ahab; no good could come of union with an idolatrous family.