Isaiah 6:7 (KJV)

Above it stood the seraphims: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly.

And one cried unto another, and said, Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory.

And the posts of the door moved at the voice of him that cried, and the house was filled with smoke.

Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, the LORD of hosts.

Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar:

Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me.

And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.

Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed.

Then said I, Lord, how long? And he answered, Until the cities be wasted without inhabitant, and the houses without man, and the land be utterly desolate,

And the LORD have removed men far away, and there be a great forsaking in the midst of the land.