Charles Spurgeon Commentary Isaiah 6:5-7

"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, Jehovah of hosts. Then flew one of the seraphim unto me, having a live coal in his hand, which he had taken with the tongs from off the altar: and he touched my mouth with it, and said, Lo, this hath touched thy lips; and thine iniquity is taken away, and thy sin forgiven." — Isaiah 6:5-7 (ASV)

Then I said, 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 my eyes have seen the King, the LORD of hosts. Then flew one of the seraphims to me, having a live coal in his hand, which he had taken with the tongs from the altar: And he laid it upon my mouth, and said, Lo, this has touched your lips; and your iniquity is taken away, and your sin purged.

Just where he felt the impurity, there he felt the expiation. His lips were unclean, and now a touch of the altar coal, a communication from the great Sacrifice, has taken all his iniquity away, and his sin is buried.