Isaiah 6:2-7

2Above 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. 3And one called to another and said: “Holy, holy, holy is the LORD of hosts; the whole earth is full of his glory!” 4And the foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke. 5And 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!” 6Then one of the seraphim flew to me, having in his hand a burning coal that he had taken with tongs from the altar. 7And he touched my mouth and said: “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.”