Symbols: Burning Coal
Isaiah's lips were impure from sin, and he realized this imperfection. Yet, he trusted the Lord to purify him. One of the seraphim, in a symbolic action, took a coal from the altar and touched his lips to cleanse them. Isaiah became a great prophet for the Lord, proclaiming the coming of a Messiah that would be a king, but also a suffering servant.
Isaiah 6:5-8; 40:10-11; 62:1-3