Tophet is ordained of old. — Literally, the Tophet, or place of burning, with perhaps the secondary sense of “a place of loathing.” Tophet was the name given to the Valley of Hinnom, outside Jerusalem, where, within the memory of living men, Ahaz had made his son to pass through the fire to Moloch (2 Kings 16:3), and where like sacrifices had taken place up to the time of Hezekiah’s accession. “The king” is, of course, the king of Assyria; but the Hebrew, “for the melek,” suggests a sarcastic reference to the god there worshipped, as if it were “for Moloch.” There was to be a great sacrifice of the Melek to the Moloch, who was as a mighty king (the name of the Ammonite god being a dialectic form of the Hebrew Melek) exulting in his victims. (Comp. for the idea Isaiah 31:9.)
The pile thereof is fire and much wood. — The word seems partly literal, and partly figurative. The king of Assyria, though he did not die at Jerusalem, is represented as burnt with stately ceremonial in Tophet. Probably, as a matter of fact, it was the burial place of the corpses that were lying round the city after the pestilence had destroyed the Assyrian army, and they were literally burnt there. For such a Moloch funeral, making the valley of Hinnom then, as it afterwards became, a fit type of Gehenna, a trench deep and wide and a mighty pyre were needed. Comp. Jeremiah 19:12, where like words are spoken of Jerusalem.