Not all sins are as obvious as murder, oppression, and adultery. Some sneak up on us.
As the Lord’s judgment turns to the nations surrounding Jerusalem, He brings up one we might not have considered: rejoicing in the misfortune of others. More particularly, rejoicing in the misfortune of God’s people. When Jerusalem fell, the Ammonites rejoiced. The Moabites considered it a confirmation that Judah was not the special people of God. The Edomites exacted revenge when Judah was weak and Philistia sought to destroy whatever of Israel the Babylonians left behind.
For all this, God promised to destroy each of these nations, and ultimately, to bring His own people back to prominence. “Then,” God says, “you will know I am the Lord.”
The world does not consider God’s people much. We are ridiculed and harassed by unbelievers. They would do us in if they could, but God won’t allow it. His promise to His people here is an eternal promise, that he loves them above all others in the world, and one day, they will be vindicated.