This lengthy section is similar to 2:6-22, but I recommend preaching it because of the new material given concerning “the branch of the Lord” in 4:2.  I would not spend too much time on the details of the judgment because this has been discussed in detail earlier in Isaiah.  However, it is important to highlight what “the branch of the Lord” will be like “in that day” (4:2).  It is also important to call our listeners to the standard of 4:3 “…he who…remains in Jerusalem will be called holy, everyone who has been recorded for life in Jerusalem…”  Again, you can see Isaiah’s purpose displayed in this section: to create a people of God who are confident of receiving deliverance, not destruction, on the Lord’s day.  That kind of holiness is received when we are washed clean by the blood of the Lamb (v. 4:4).