For Tophet is ordained of old; yea, for the king it is prepared; he hath made it deep and large: the pile thereof is fire and much wood; the breath of the LORD, like a stream of brimstone, doth kindle it. For Tophet is ordained - Tophet is a valley very near to Jerusalem, to the southeast, called also the valley of Hinnom or Gehenna; where the Canaanites, and afterwards the Israelites, sacrificed their children, by making them pass through the fire, that is, by burning them in the fire, to Molech, as some suppose. It is therefore used for a place of punishment by fire; and by our blessed Savior in the Gospel for hell-fire, as the Jews themselves had applied it. See Chald. on Isaiah 33:14, where מוקדי עלם mokedey olam is rendered "the Gehenna of everlasting fire." Here the place where the Assyrian army was destroyed is called Tophet by a metonymy; for the Assyrian army was destroyed probably at a greater distance from Jerusalem, and quite on the opposite side of it: for Nob is mentioned as the last station, from which the king of Assyria should threaten Jerusalem, Isaiah 10:32, where the prophet seems to have given a very exact chorographical description of his march in order to attack the city; which however he never reached. - L.
Commentary on the Bible, by Adam Clarke [1831].