Isaiah 6:5-7

Then I said, “Woe is me, for I am ruined! Because I am a man of unclean lips, And I live among a people of unclean lips; For my eyes have seen the King, the LORD of hosts.” Then one of the seraphim flew to me with a burning coal in his hand, which he had taken from the altar with tongs. He touched my mouth with it and said, “Behold, this has touched your lips; and your iniquity is taken away and your sin is forgiven.”