In the year that King Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and the train of his robe filled the temple. Above him stood the seraphim. Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew. And one called to another and said: “Holy, holy, holy is the Lord of hosts; the whole earth is full of his glory!”
And the foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke. And I said: “Woe is me! For I am lost; for I am a man of unclean lips, and I dwell in the midst of a people of unclean lips; for my eyes have seen the King, the Lord of hosts!”
Then one of the seraphim flew to me, having in his hand a burning coal that he had taken with tongs from the altar. And he touched my mouth and said: “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.”
And I heard the voice of the Lord saying, “Whom shall I send, and who will go for us?” And the whole court grew strangely silent as I closed my eyes in prayerful meditation. Then finally I opened my eyes and noticed that all the seraphim were staring at me.
“What?” I asked. “Surely you don’t expect someone of unclean lips, from among a people of unclean lips, to presume to volunteer for a mission from the Lord of Hosts?”
And the Seraph hovering nearest to me shook the tongs that were still in his hands, and said, “Did I not just touch your lips with a coal from the altar?”
“But surely, sir, you cannot expect me to presume I am chosen, called, and/or forgiven on the basis of a visible sign!”