Then flew - Isaiah is represented as standing out of the temple; the seraphim as in it.
Having a live coal - The Vulgate renders this, ‘A stone.’ This is, probably, the original meaning of the word; see 1 Kings 19:6. It at first denoted a hot stone which was used to roast meat upon. It may also mean a coal, from its resemblance to such a stone.
From off the altar - The altar of burnt-offering. This stood in the court of the priests, in front of the temple; see the notes at Matthew 21:12. The fire on this altar was at first kindled by the Lord, Leviticus 9:24, and was kept continually burning; Leviticus 6:12-13.