Libnah — Libnah seems to have set up for a free state. And the reason is here given, both why God permitted it, and why they did it, because Jehoram was become an idolater. While he adhered to God, they adhered to him; but when he cast God off, they cast him off. Whether this would justify them in their revolt or no, it justified God's providence which suffered it.
Related Commentaries of 2 Chronicles 21:10
2 Chronicles 21:10
10 So the Edomites revolted from under the hand of Judah unto this day. The same time also did Libnah revolt from under his hand; because he had forsaken the LORD God of his fathers.