1. "The city is left in ruins" (1-13)

The scope of God's judgment would cover the earth and all will be judged equally. The reason is that the earth is defiled by its people who disobeyed God's laws and broke the covenant. The city of Jerusalem would be spared destruction by Assyria. But they would not escape this curse. They would bear their guilt, and the city would be completely laid waste. Only a remnant would remain on the earth (6,13).

2. "The LORD Almighty will reign on Mount Zion" (14-23)

In the context of such destruction, why would the remnant sing songs of joy? Their voices from all the earth would lift up to sing: "Glory to the Righteous One!" The devastation of the earth will be seen as a righteous act by the Holy God, in contrast with the cruel acts of Assyria. Yet Isaiah, seeing the treachery around him, mourned. He knew they would be destroyed. Yet this too would not be the end. The Lord will reign in Jerusalem. We look forward to this glorious Day as well.