1 Kings 8:51

They be thy people; for howsoever they may sin against thee, or suffer from men, yet still remember that they are thy peculiar people, and therefore do thou pity, and pardon, and save them. The furnace of iron; so called, either from the metal melted in it; or rather, from the matter of which it consisted, an iron furnace being more hot and terrible than one of brick or stone. He understands hereby their cruel bondage and painful labours. See Poole on "Deuteronomy 4:20".