Isaiah 6:2-7

2Seraphim were standing above Him. Each had six wings: with two he covered his face and with two he covered his feet, and with two he flew.

3One called out to another, and said: “Holy, holy, holy, is Adonai-Tzva’ot! The whole earth is full of His glory.”

4Then the posts of the door trembled at the voice of those who called, and the House was filled with smoke.

5Then I said: “Oy to me! For I am ruined! For I am a man of unclean lips, and I am dwelling among a people of unclean lips. For my eyes have seen the King, Adonai-Tzva’ot!”

6Then one of the seraphim flew to me, with a glowing coal in his hand, which he had taken with tongs from the altar.

7He touched my mouth with it and said: “Behold, this has touched your lips. Your iniquity is taken away, and your sins atoned for.”