InhisdaystheEdomitesrevolted - See on 2 Kings 8:21; (note).
Matthew Henry
Concise Bible Commentary
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.
SDA Bible Commentary (limited)
Volume 1-7
8. The Edomites revolted. During the reign of Jehoshaphat, Edom had no king (1 Kings 22:47), and the country seems to have been under the control of Judah, for Jehoshaphat based his navy at Ezion-geber (2 Chron. 20:36), south of Edom.