Now, Isaiah says that in the same year that King Uzziah died, he (Isaiah) had a really intense vision of God seated upon his throne:
The hem of God's robe hangs down and fills the temple. Seraphim—angels with six wings—are attending on God and singing his praises. They cover their faces with two of their wings, cover their feet with another two, and use the remaining pair to fly.
The entirety of the throne room-temple fills with smoke. Isaiah cries out, saying that he is a man of unclean lips living among a people of unclean lips, yet he's somehow managed to still see God.
One of the Seraphim comes down to fix this problem. He takes a burning coal from the temple and presses it against Isaiah's mouth. It hurts—but hey, his lips are clean now, his sins have been purified, and now he can prophesy.
Isaiah hears God ask who can go and speak to his people, and Isaiah eagerly volunteers.
What?? It Was in the Stump All Along!
Next, God tells Isaiah what he should say to the people of Judah and Jerusalem. It's basically a set of somewhat paradoxical commands: "Keep listening, but do not understand; keep looking, but do not understand."
God says that Isaiah should make the people unable to understand what's going on. He says that Isaiah should prevent them from understanding what God desires of them, making sure that they're unable to be healed and forgiven. (This might be an ironic way of saying that, though. By telling them the right things to do, Isaiah will make them blind to the truth, because they'll be so naturally opposed and unwilling to listen to it.)
Isaiah is supposed to keep this mission up until cities are totally demolished, and the country is thoroughly depopulated (through death and through exile).
God says that, if even ten percent of the population remains, it will still be subject to destruction, like a tree cut down until it's just a stump.
But he also says (cryptically), the holy seed (the power that will redeem the people) will be hidden in the stump. Hmm.