Charles Ellicott Commentary 2 Kings 3:18

"And this is but a light thing in the sight of Jehovah: he will also deliver the Moabites into your hand." — 2 Kings 3:18 (ASV)

Is but a light thing. — Will be a light thing (1 Kings 16:31).

He will deliver the Moabites. —The contrary of Jehoram’s expectation (2 Kings 3:10; 2 Kings 3:13).