It seems equally likely that the import of the section is that the Israel of [Isaiah] 2:6-4:1 can only fulfill the dstiny given her in 2:2-4 by experiencing the judgment expressed throughout 2:6-4:1 and the purification described in 4:2-6. This schema would correspond well with the thought of ch. 1 and indeed the whole book: proud, self-sufficient Israel can become the witness to the greatness of God only when she has been reduced to helplessness by his just judgment and then restored to life by his unmerited grace.
-- John N. Oswalt, The Book of Isaiah Chapters 1-39