Also, explain the fire will not be quenched. We need to consider the style of literature, and devices that God uses as he inspires Isaiah. Much of Isaiah is written in poetic style, with devices like alliteration, wordplay, personification and hyperbole contributing to the richness of God's inspiration. The immediate context of the passage and chapter help us to understand when they are symbolic and when they are literal. This is the fate, in Isaiah, of those who have rebelled against God.
Fire is used in Isaiah to symbolize both purification and judgement.
Refining fires are spoken of, as is the furnace of affliction. Because understanding the Bible properly is not a hit or miss thing. Isaiah is filled with word pictures about the fate of those who rebel against him. They will spread out their hands in it, as a swimmer spreads out his hands to swim. Oh no, this must be symbolic.