God again offers more comfort, saying that he'll let water flow through the land for the thirsty, and promising that Israel's descendants will spring up like green tamarisk trees.
These descendants will acknowledge God in different ways: some will be called by Jacob's name, or some will adopt the name of Israel.
God proclaims (again) how incomparable he is, daring them to name any God who equals him. (We can infer, from the flow of the text, that this dare is met by the sound of crickets.) He concludes that he's the only one.
He further attacks idols, their devotees, and the people who make them, saying that they'll all be ashamed.
The Idol Factory Grand Tour
Now, God goes through the whole process of idol-making—kind of like the "How It's Made" segment from Mr. Rogers' Neighborhood (which no one reading this summary probably remembers—we are old).
First, the ironsmith forges the iron, getting tired and week as he hammers. Then, the carpenter works with wood and does his whole thing, planning out his wooden idol. God points out that the carpenter uses for fuel and for cooking the same wood that he uses to make his idol. So, says God, how deluded can you get, worshipping the wood you'd otherwise burn? God announces that the carpenter is the kind of dude who feasts on ashes. (This is sort of like a kid on a playground announcing that lil' Bobby eats worms)
God tells Israel to remember all this, since he's swept away its sins like clouds from the sky.
Isaiah asks the heavens and the earth to sing with joy for how God has redeemed Israel.
God proclaims his glory as the world's savior, who made everything, who formed the people of Israel in the womb, and who can frustrate fortune-tellers and pagan magicians.
He says he will rebuild Judah, dry up the rivers, use King Cyrus of Persia to carry out his purpose, and make sure that Jerusalem and its temple are rebuilt.