Isaiah 6:7

and he laid it upon my mouth, he caused the glowing coal to come into contact with the prophet's lips, and said, Lo, this hath touched thy lips; and thine iniquity is taken away and thy sin purged, atoned for. The act of the angel evidently had a symbolical meaning, first of all with reference to the atonement made in and through the person of Jesus Christ, the work of redemption carried out in accordance with the Triune God's counsel. Not only, however, is the prophet, sinful man as he was, assured of the grace of God, but the Lord also imparts special strength to him and fits him to be the instrument of His inspiration.