The rest of chapter 4 is a dramatic flip. After exposing the flaws of present day Jerusalem to dramatic, forensic, poetic scrutiny, Isaiah switches the focus abruptly to the future.
All that filth is going to be washed away. God isn't finished with Jerusalem. We're back to the vision of what the perfect Jerusalem could be: holy, beautiful, glorious.
Who's this branch? We'd better get used to this idea, it's going to crop up a lot. Let's pretend we don't know what it means for a minute. Perhaps you don't know - fine then!!
Picture an old, gnarly, broken-down tree.
Now imagine a new, young branch, growing out from it, near the root. New life and energy, bursting out from something that seemed nearly dead. Young, fresh, full of sap and vigour, encapsulating all the qualities that the old tree had in its far-off youth.
This righteous branch, this shoot from the stump, is a sign of new hope when all around looked tired and old and as good as dead.
The dream of what Israel could be - a chosen race so magnetically attractive that people would stream to the hill of Zion to meet the living God - this dream seems lost, and Isaiah is the first to tell us so.
But he also tells us that the there's life in the old tree yet. That God hasn't given up on his plans for Judah and Jerusalem.
One day, God's presence will be back. The pillar of cloud by day and fire by night that led them through the wilderness will again hover over Jerusalem, his love will overshadow them like a bridal canopy.