Isaiah 6:1-8 English Standard Version (ESV)
1 In the year that King Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and the train[a] of his robe filled the temple. 2 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. 3 And one called to another and said:
“Holy, holy, holy is the Lord of
hosts;
the whole earth is full of his glory!”[b]
4 And the foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke. 5 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!”
6 Then one of the seraphim flew to me, having in his hand a burning coal that he had taken with tongs from the altar. 7 And he touched my mouth and said: “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.”
8 And I heard the voice of the Lord saying, “Whom shall I send, and who will go for us?” Then I said, “Here I am! Send me.”
Isaiah begins with, “I saw the Lord.” No one comes in the presence of the Lord who is unworthy, no one. Yet here is Isaiah and this is his response to being in the presence of the Lord, “I am lost”. This is what Adam should have answered to God yesterday in Genesis 3. I considered Isaiah’s words, knowing he already is in the presence of the Lord and therefore worthy. Isaiah confesses his unworthiness, not of a truth but as an emotion, his personal feelings.
Then the angel comes with a coal and purges Isaiah lips and takes away Isaiah’s shame. He did not cover it as God did for Adam and Eve with the skins of animals. The coal came from the alter. Now Isaiah knows of a certainty that his sins are not just covered but removed altogether. Notice the confident reply from Isaiah to the Lord’s request. “Here I am.”