We saw Isaiah give a message of judgment and hope for Jerusalem. Isaiah accused the cities leaders of Rebellion, Idolatry, injustice.
God said He was going to judge the city by sending the nations to conquer Israel. God said it would be like a purifying fire that would burn away all that’s worthless.
To create a new Jerusalem (millennial kingdom) Isaiah said that's when all people would come from around the world to worship God.