Take heed, and be quiet... — The prophet meets the fears of the king by words of comfort. The right temper for such a time was one of calm courage, waiting on the Lord (Isaiah 30:15).
Neither be fainthearted. — Literally, let not thine heart be soft.
For the two tails of these smoking fire brands. — The two powers that Ahaz dreaded were, in the prophet’s eyes, but as the stumps of two smoking torches. Their flame was nearly out. It would soon be extinguished.
The son of Remaliah. — There is a touch of scorn in the omission of the king’s name. So men spoke scornfully of Saul as “the son of Kish” (1 Samuel 10:11), and Saul himself of David as “the son of Jesse” (1 Samuel 20:30). It pointed out the fact that Pekah was after all but an upstart adventurer, who had made his way to the throne by rebellion and murder.