Charles Ellicott Commentary 2 Chronicles 21:9

"Then Jehoram passed over with his captains, 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." — 2 Chronicles 21:9 (ASV)

Then Jehoram went forth. — And Jehoram passed over.

With his princes. — Captains (‘im sârâv); Kings, to Zair, which appears to be a corruption of to Seir. The chronicler has substituted an intelligible for an obscure expression.

And he rose up by night, and smote the Edomites which compassed him in. —Literally, and it came to pass, he rose. Brief as the notice is, it is evident that the verse relates not a victory of Jehoram’s, but his desperate escape by cutting his way through the enemy’s troops, which had surrounded him and his forces. (See 2 Kings 8:21, where it is added, and the people fled to their tents.) (Syriac: And Jehoram passed over with his captains; and all his chariots with him. And it came to pass that when he rose in the night, he destroyed the Edomites, and the captains of the chariots came with him.)