8 In his days the Edomites revolted against Judah's authority, and made a king over themselves. 9 So Jehoram went out with his officers, and all his chariots with him. And he rose by night and attacked the Edomites who had surrounded him and the captains of the chariots. 10 Thus Edom has been in revolt against Judah's authority to this day. At that time Libnah revolted against his rule, because he had forsaken the Lord God of his fathers.
Matthew Henry's Commentary on 2 Chronicles 21:8-10
Commentary on 2 Chronicles 21:1-11
(Read 2 Chronicles 21:1-11)
Jehoram hated his brethren, and slew them, for the same reason that Cain hated Abel, and slew him, because their piety condemned his impiety. In the mystery of Providence such men sometimes prosper for a time; but the Lord has righteous purposes in permitting such events, part of which may now be made out, and the rest will be seen hereafter.