“But if ye will not hearken unto me to hallow the Sabbath day, and not bear a burden, even entering in at the gates of Jerusalem on the Sabbath day; then will I kindle a fire in the gates thereof, and it shall devour the palaces of Jerusalem, and it shall not be quenched.”
From this text we certainly can learn the meaning that was attached to the expression, “unquenchable fire,” by the Hebrew people. This fire was not to be quenched, therefore it was unquenchable. But it was to be kindled in the gates of Jerusalem, and devour the palaces thereof. It was therefore literal, natural, fire. But how could a fire of this kind, thus kindled, be supposed to be a fire that would burn eternally? They certainly would not so understand it. No more should we. Moreover, this threatening of the Lord by Jeremiah was fulfilled. 2 Chron. 36:19: “And they burnt the house of God, and brake down the wall of Jerusalem, and burnt all the palaces thereof with fire, and destroyed all the goodly vessels thereof.” Verse 21. “To fulfill the word of the Lord by Jeremiah.” Thus Jerusalem was burned according to Jeremiah’s prediction that it should be consumed in unquenchable fire. But how long did that fire burn? Only till it had reduced to ashes the gates and palaces on which it preyed. Unquenchable fire is therefore simply a fire that is not quenched, or does not cease, till it has entirely consumed that which causes or supports it. Then it dies out of itself, because there is nothing more to burn. The expression does not mean a fire that must absolutely eternally burn, and that consequently all that is cast therein to feed the flame must forever be preserved by having the portion consumed immediately renewed.
To the wicked the threatened fire is unquenchable because it will not be quenched, or caused to cease, till it has entirely devoured them.
Ps. 37: 20: “But the wicked shall perish, and the enemies of the Lord shall be as the fat of lambs; they shall consume; into smoke shall they consume away.” Mal. 4: 3: “And ye shall tread down the wicked; for they shall be ashes under the soles of your feet in the day that I shall do this saith the Lord of hosts.”
Ezekiel speaks of unquenchable fire in a similar manner.
Eze. 20: 47, 48: “Thus saith the Lord God: Behold I will kindle a fire in thee, and it shall devour every green tree in thee, and every dry tree; the flaming flame shall not be quenched, and all faces from the south to the north shall be burned therein. And all flesh shall see that I the Lord have kindled it: it shall not be quenched.”
Though this is doubtless figurative language, denoting sore calamities upon a certain land called the forest of the south field, it nevertheless furnishes an instance of how the expression, unquenchable fire, was then used and understood; for that generation many ages ago perished, and those judgments long since ceased to exist.
Isaiah not only speaks of the unquenchable fire, but he couples with it the undying worm, the same as the language in Mark:
Isa. 66: 24: “And they shall go forth and look upon the carcasses of the men that have transgressed against me: for their worm shall not die, neither shall their fire be quenched, and they shall be an abhorring unto all flesh.”
This is undoubtedly the language from which the expression in Mark is borrowed; but a moment’s examination of it will show that the worm is not the remorse of a guilty conscience, but that, like the fire, it is something external to, and distinct from, the objects upon which it preys; and moreover that those upon whom it feeds are not the living, but the dead: it is the “carcasses” of the men that have transgressed against the Lord. In Isa. 14: 11, and 51: 8, the prophet again speaks of the worm as an agent of destruction, but it is always in connection with death. It is thus evident that the terms employed by our Lord in describing the doom of the wicked would convey to the minds of his hearers the very opposite of the idea of eternal life in misery.