Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar:
Then flew one of the seraphim unto me. The seraph had been in the temple, Isaiah outside of it.
Having a live coal - literally, a hot stone ( ritspah (H7531)) used, as in some countries in our days, to roast meat with; e.g., the meat of the sacrifices. Fire was a symbol of purification, as it takes the dross out of metals (Malachi 3:2-3).
Which he had taken with the tongs from off the altar - of burnt offering in the court of the priests before the temple. The fire on it was at first kindled by God (Leviticus 9:24), and was kept continually burning.