The Furnace & the Refiner's Fire · The Symbolism of Scripture
The Furnace & the Refiner's Fire
A furnace is fire that has been given a container and a job. In Scripture the passage almost always says what the job was, and the outcome is never the destruction of what was put in.
THE ARTWORKTurner painted Daniel 3 at its turning point: the three men stand unhurt inside the flame while the court looks on. The fire fills the canvas, and it is not winning.
What It Stands For
Not fire. Fire with walls around it and a job to do.
Fire falls on Sodom and comes down on Carmel. A furnace is built, and a built thing has a purpose. That is the difference between this symbol and the wider symbol of fire.
The commentators are specific about what kind of furnace Deuteronomy means. Not a baker’s oven: a smelting pit thirty feet deep, run at the highest heat a bronze-age economy could produce. Jamieson, Fausset and Brown split the metaphor in five words at Jeremiah 11:4: “"Furnace" expresses the searching ordeal; "iron," the long duration of it.”
But the Lord hath taken you, and brought you forth out of the iron furnace--that is, furnace for smelting iron. A furnace of this kind is round, sometimes thirty feet deep, and requiring the highest intensity of heat.
Jamieson, Fausset & Brown· Commentary Critical and Explanatory on the Whole Bible, 1871Scottish, nineteenth century
Deuteronomy 4:20
Clarke: Israel worked Egypt's furnacesan inference from the word, and he says so
From this mention of the word iron furnace there can be little doubt that the Israelites were employed in Egypt in the most laborious works of metallurgy. Digging, smelting, and forging of iron in so hot a climate must have been oppressive work indeed.
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Deuteronomy 4:20
Clarke reasons from the word rather than from a record. “There can be little doubt” is an inference, not a citation.
The Words Underneath
The Hebrew and Greek behind the symbol, each a door to its full word study.
kûwr: a pot or furnace (as if excavated)
The Old Testament's smelting furnace, defined by its construction: a pot or furnace as if dug out. This is Egypt in Deuteronomy 4:20.
9 occurrences · open the word study →
tsâraph: to fuse (metal), i.e. refine (literally or figuratively)
To smelt or refine. The verb of Psalm 12:6 and Zechariah 13:9, and the word behind the Refiner of Malachi 3.
33 occurrences · open the word study →
bâchan: to test (especially metals)
To test, the way an assayer tests metal. Job 23:10 and Proverbs 17:3 both use it for what God does with hearts.
29 occurrences · open the word study →
káminos: a furnace
The New Testament's furnace. Matthew 13 uses it for judgment; Revelation 1:15 for the feet of the risen Christ.
4 occurrences · open the word study →
dokímion: a testing
The proving that shows a thing genuine. Peter's word for the trial of faith in 1 Peter 1:7.
2 occurrences · open the word study →
Nine Furnaces, and What Came Out of Each
The outcome column, in the passages' own words.
| Where | What goes in | What the passage says comes out |
|---|---|---|
| Deuteronomy 4:20 | A nation, in Egypt, called an iron furnace | “to be unto him a people of inheritance” |
| Jeremiah 11:4 | The same furnace, named again a lifetime later | “so shall ye be my people, and I will be your God” |
| Job 23:10 | A man who has lost everything | “I shall come forth as gold” |
| Psalm 12:6 | The words of the LORD, put beside tried silver | “purified seven times” |
| Proverbs 17:3 | Silver in the fining pot, gold in the furnace | “but the LORD trieth the hearts” |
| Isaiah 48:10 | A people who had not come out pure | “I have chosen thee in the furnace of affliction” |
| Daniel 3:27 | Three men, bound, in a furnace heated seven times over | “nor was an hair of their head singed” |
| Zechariah 13:9 | A third part, brought through the fire | “they shall call on my name, and I will hear them” |
| 1 Peter 1:7 | Faith, tried the way gold is tried | “might be found unto praise and honour and glory” |
Yet the LORD has taken you and brought you out of the iron furnace, out of Egypt, to be the people of His inheritance, as you are today.The furnace and the purpose in one sentence, with no gap between them.
This third I will bring through the fire;I will refine them like silverand test them like gold.They will call on My name,and I will answer them.I will say, ‘They are My people,’and they will say, ‘The LORD is our God.’”Refining described, then the outcome given as a conversation: they call, and He answers.
One limit keeps the symbol honest. A furnace text is not a promise that every hard thing is a refining. Scripture also has fire that only destroys, and other words for it. What these nine passages share is that each names its own product.
Refined, But Not With Silver
The one furnace sentence nobody agrees about.
See, I have refined you, but not as silver; I have tested you in the furnace of affliction.Two clauses. The first is disputed by every commentator who has touched it; the second is not disputed at all.
“I have refined thee, but not with silver.” Nobody is sure what that clause means. This page shows the disagreement instead of picking a winner. Whichever reading is right, the sentence ends where nobody disputes it: the furnace of affliction is where the choosing happened.
Many different interpretations of this have been proposed. Jerome renders it, Non quasi argentum - Not as silver. The Septuagint, Οὐχ ἕνεκεν ἀργυρίου ouch heneken arguriou - Not on account of silver. Grotius explains it, I have a long time tried thee by afflictions, but nothing good appears in thee; that is, I have not found you to be silver, or to be pure, as when a worker in metals applies the usual heat to a mass of ore for the purpose of separating the dross, and obtains no silver.
Albert Barnes· Notes, Explanatory and Practical, on the Old and New Testaments, 1851Presbyterian
Isaiah 48:10
The four readings, and a fact about melting pointsJerome · the Septuagint · Grotius · Rosenmüller
Not as silver (Jerome): the refining was of a different kind. Not on account of silver (the Septuagint): not for profit; God gained nothing by it. I did not find silver in you(Grotius): the process was run and no silver came out, which is Jeremiah 6:30’s verdict in gentler words. Not with the heat silver needs (Rosenmüller): the fire was deliberately held below full strength.
Rosenmuller supposes it means, that he had not tried them with that intensity of heat which was necessary to melt and refine silver; and remarks, that those skilled in metals observe that gold is easily liquified, but that silver requires a more intense heat to purify it.
Albert Barnes· Notes, Explanatory and Practical, on the Old and New Testaments, 1851Presbyterian
Isaiah 48:10
The metallurgy behind the last reading is real: gold melts at a lower temperature than silver refines at, so a refiner choosing his heat is choosing what he will put the metal through. Whether Isaiah meant it, the text does not say.
The other clause has a textual wrinkle. Clarke records a manuscript reading I have tried thee where the received text reads I have chosen thee, one Hebrew letter apart:
For בחרתיך becharticha, I have chosen thee, a MS. has בחנתיך bechanticha, I have tried thee. And so perhaps read the Syriac and Chaldee interpreters
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Isaiah 48:10
The Hottest Furnace in the Bible
An inventory of what the fire actually burned.
At this, Nebuchadnezzar was filled with rage, and the expression on his face changed toward Shadrach, Meshach, and Abednego. He gave orders to heat the furnace seven times hotter than usual,The one furnace in Scripture built for nothing but killing, stoked past its working temperature by a man in a rage.
seven times more than it was wont--literally, "than it was (ever) seen to be heated." Seven is the perfect number; that is, it was made as hot as possible.
Jamieson, Fausset & Brown· Commentary Critical and Explanatory on the Whole Bible, 1871Scottish, nineteenth century
Daniel 3:19
“As hot as possible” is the point. Every other furnace in Scripture runs at a chosen heat, for a product. This one runs at maximum, to kill. Then the chapter does something unusual: it audits the fire.
- The men who carried them upconsumed
“the flame of the fire slew those men that took up Shadrach”
Daniel 3:22 - The ropesconsumed
“I see four men loose, walking in the midst of the fire”
Daniel 3:25 - Their bodiesuntouched
“upon whose bodies the fire had no power”
Daniel 3:27 - Their hairuntouched
“nor was an hair of their head singed”
Daniel 3:27 - Their clothesuntouched
“neither were their coats changed”
Daniel 3:27 - Even the smelluntouched
“nor the smell of fire had passed on them”
Daniel 3:27
Not bound as the three were, when cast in; but quite at liberty in their hands and feet, and separate from one another.
John Gill· Exposition of the Old Testament, 1763Particular Baptist
Daniel 3:25
From the fact that he saw these men now loose, and that this filled him with so much surprise, it may be presumed that they had been bound with something that was not combustible - with some sort of fetters or chains. In that case it would be a matter of surprise that they should be loose, even though they could survive the action of the fire.
Albert Barnes· Notes, Explanatory and Practical, on the Old and New Testaments, 1851Presbyterian
Daniel 3:25
What surprised the king was not that the men were alive but that they were loose. The one thing the fire removed was the thing holding them.
“Look!” he exclaimed. “I see four men, unbound and unharmed, walking around in the fire—and the fourth looks like a son of the gods!”A pagan king counts four where three were thrown in.
Jesus Christ, the Angel of the covenant, did sometimes appear before his incarnation. Those who suffer for Christ, have his gracious presence with them in their sufferings, even in the fiery furnace, even in the valley of the shadow of death, and therefore need fear no evil.
John Wesley· Explanatory Notes upon the Old Testament, 1765Methodist
Daniel 3:25
The fourth man in the fire is Christ before His incarnation. That is taught here at full strength, and the older commentators teach it too. The words in verse 25 are Nebuchadnezzar’s, and his Aramaic can carry “a son of the gods”. The Angel of YHWH works this question out at length.
Clarke checked the natural explanations firstfire-walkers, Varro's ointment, and why they fail here
But Varro tells us that they anointed the soles of their feet with a species of unguent that preserved them from being burnt. Very lately a female showed many feats of this kind, putting red hot iron upon her arms, breasts, etc., and passing it over her hair without the slightest inconvenience; but in the case of the three Hebrews all was supernatural, and the king and his officers well knew it.
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Daniel 3:27
Clarke looked for a natural explanation before ruling it out. The chapter closes that door itself: the men who only came near the opening were killed by the same fire.
The Refiner Sits Down
One verb, and the whole picture turns.
But who can endure the day of His coming? And who can stand when He appears? For He will be like a refiner’s fire, like a launderer’s soap.Two cleaning trades named side by side. Only one uses fire.
And He will sit as a refiner and purifier of silver; He will purify the sons of Levi and refine them like gold and silver. Then they will present offerings to the LORD in righteousness.The verb the whole verse turns on. He does not light it and leave.
He shall sit as a refiner - Alluding to the case of a refiner of metals, sitting at his fire; increasing it when he sees necessary, and watching the process of his work.
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Malachi 3:3
He sits because silver cannot be left alone in a fire. The refiner stays at the crucible, raises the heat when it needs raising, and watches the metal the whole time. The difference between purified and ruined is minutes and attention. The verse does not say God is patient with the process. It says He does not leave it.
More from the workshop: Gill, Kimchi, and the fuller's soapan eight-hundred-year-old question about who is sitting
but it is to be understood of the Lord himself, and expresses his diligence in sitting and separating good men and principles from bad ones, just as silver is purified and refined from dross.
John Gill· Exposition of the Old Testament, 1763Particular Baptist
Malachi 3:3
Gill records that David Kimchi (Radak, the Provençal grammarian, about 1200) read the sitter as the day rather than the Lord, like a judge taking his seat. Gill disagrees and says why. Both readings turn on the same posture.
Like fullers soap - כברית keborith, from ברר barar, to cleanse, any thing that deterges. Kali, or fern ashes, or such things. I doubt whether the composition which we call soap, was known in ancient times.
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Malachi 3:2
The pairing in verse 2 does real work. A fuller cleans wool by soaking, beating and treading it in alkali. A refiner cleans silver by burning everything that is not silver. Malachi names both trades, and the sons of Levi get the one with the fire.
Seven Times, and a Furnace of Earth
What a psalm meant by a number.
The words of the LORD are flawless, like silver refined in a furnace, like gold purified sevenfold.The standard the psalm reaches for when it wants to say God's words are unadulterated.
The word here rendered furnace properly means a workshop. Perhaps it corresponds nearly with our word laboratory, as the term is now used by chemists. It evidently refers to some place where the metal was tried and purified. The words rendered of earth literally mean on the earth, or in the earth?
Albert Barnes· Notes, Explanatory and Practical, on the Old and New Testaments, 1851Presbyterian
Psalm 12:6
Not a furnace made of earth. A furnace inthe ground: a working pit, a laboratory. The refiner does not count passes; he watches the surface. While anything foreign remains, the molten metal moves. When it goes still, it is done. “Seven times” is the psalm’s way of saying finished.
Clarke describes the process itselfcupellation: lead, heat, and the moment the metal goes still
The metal to be purified must be mingled with lead, and laid on the cupel, and exposed to a strong heat in an air furnace. The impurities of the metal will be partly absorbed, and partly thrown off in fume. The metal will continue in a state of agitation till all the impurities are thrown off; it will then become perfectly still, no more motion appearing, which is the token that the process is completed
Adam Clarke· Commentary on the Bible, 1832Wesleyan
Psalm 12:6
But what is this gold refined by the spiritual fire? The prophet teaches, saying "the words of the Lord are pure words, like silver refined and tested seven times
Oecumenius· Commentary on Revelation, 550Greek, sixth century
Revelation 3:18
Where It Points
What the fire is for, said out loud.
so that the proven character of your faith—more precious than gold, which perishes even though refined by fire—may result in praise, glory, and honor at the revelation of Jesus Christ.The purpose stated, and the comparison made, with gold coming off worse.
I counsel you to buy from Me gold refined by fire so that you may become rich, white garments so that you may be clothed and your shameful nakedness not exposed, and salve to anoint your eyes so that you may see.Said to Laodicea, three verses after the church called itself rich and in need of nothing.
Peter’s comparison is sharper than it looks. Gold is the standard for what survives fire, and Peter says faith is more precious, because gold in the end perishes. The metal that outlasts every fire does not outlast everything.
Gold in the furnace is advanced to the brightness of its nature, whilst it loses the dross.
Gregory the Great· Morals on the Book of Job, Book XVI, 604Latin, sixth century
Job 23:10
Because the saints saw that the divine fire would cleanse them and benefit them, they did not shrink back from or get discouraged by the trials which they faced. Rather than being hurt by what they went through, they grew and were made better, shining like gold that has been refined in a fire.
Athanasius of Alexandria· Festal Letters 10, 373Alexandrian, fourth century
1 Peter 1:7
Gregory’s sentence is the one to keep: gold in the furnace is advanced to the brightness of its nature. Nothing is added to the gold. What comes off is everything that was never gold.
Barnes: the grain of gold in an ordinary manwhat the fire is looking for may be very small
Wonderful as is the separation of the pure metal from the dross with which it has mingled, there is something yet more wonderful in the divine discipline which purifies the good that lies hid, like a grain of gold, even in rough and common natures, and frees it from all admixture of evil.
Albert Barnes· Notes, Explanatory and Practical, on the Old and New Testaments, 1851Presbyterian
Proverbs 17:3
What Scripture says outright
- Deuteronomy 4:20
Egypt is named an iron furnace, and the same sentence gives the outcome: a people of inheritance. The image and its meaning arrive together.
- Isaiah 48:10
“I have chosen thee in the furnace of affliction.” Whatever the first half of the verse means, the furnace is named as the place of choosing.
- Malachi 3:3
The verb is sit, and the purpose is stated in the same verse: that they may offer an offering in righteousness.
- 1 Peter 1:7
The New Testament gives the reason for the whole symbol in one sentence, and names what it is worth more than.
What readers have heard in it
Long-standing readings.
- Psalm 12:6
That the seven purifications are the sevenfold Spirit of Isaiah 11 and the seven beatitudes. Augustine’s reading: “"Purified seven times:" by the fear of God, by godliness, by knowledge, by might, by counsel, by understanding, by wisdom.” Beautifully made, and not what the psalm says it is counting.
- Daniel 3:19
That the seven-times heat is a symbol of perfect judgment. The number is the chapter’s way of saying as hot as it would go; the theology is supplied by the reader.
- Isaiah 48:10
Every confident settlement of “not with silver”. Four serious proposals are on this page, and the clause is unresolved.
Its Presentation Through Scripture
Twelve furnace passages, in the order the Bible sets them. Open the walk to read each one.
Open the walk: all twelve furnace passageseach stop carries its verse text and one line on what it adds
Yet the LORD has taken you and brought you out of the iron furnace, out of Egypt, to be the people of His inheritance, as you are today.
The first furnace in Scripture is a country. Egypt is called an iron furnace, and the sentence says what the heat was for.
which I commanded your forefathers when I brought them out of the land of Egypt, out of the iron furnace, saying, ‘Obey Me, and do everything I command you, and you will be My people, and I will be your God.’
Eight centuries later Jeremiah uses the same phrase for the same country, with the same purpose attached.
Yet He knows the way I have taken; when He has tested me, I will come forth as gold.
A man who has lost everything says the one thing he is sure of: he will come out as gold.
The words of the LORD are flawless, like silver refined in a furnace, like gold purified sevenfold.
The image measures God's own words: silver run through the workshop furnace to completion.
A crucible for silver and a furnace for gold, but the LORD is the tester of hearts.
Each metal has its proper apparatus. The proverb names them, then names who does that work on a man.
See, I have refined you, but not as silver; I have tested you in the furnace of affliction.
The hardest sentence on this page: refined, but not with silver. In the same breath, chosen.
At this, Nebuchadnezzar was filled with rage, and the expression on his face changed toward Shadrach, Meshach, and Abednego. He gave orders to heat the furnace seven times hotter than usual,
A furnace deliberately overheated by an angry king. The one time in Scripture a furnace is used purely to kill.
and when the satraps, prefects, governors, and royal advisers had gathered around, they saw that the fire had no effect on the bodies of these men. Not a hair of their heads was singed, their robes were unaffected, and there was no smell of fire on them.
The chapter lists what the fire failed to touch: bodies, hair, coats, even the smell.
And He will sit as a refiner and purifier of silver; He will purify the sons of Levi and refine them like gold and silver. Then they will present offerings to the LORD in righteousness.
The posture that changes the whole picture. The Refiner does not light the fire and leave. He sits down.
This third I will bring through the fire;I will refine them like silverand test them like gold.They will call on My name,and I will answer them.I will say, ‘They are My people,’and they will say, ‘The LORD is our God.’”
Refining ends in a conversation: they call, and He answers.
so that the proven character of your faith—more precious than gold, which perishes even though refined by fire—may result in praise, glory, and honor at the revelation of Jesus Christ.
The New Testament states the reason and ranks the comparison: gold perishes, and the thing being tried does not.
I counsel you to buy from Me gold refined by fire so that you may become rich, white garments so that you may be clothed and your shameful nakedness not exposed, and salve to anoint your eyes so that you may see.
The last word: gold tried in the fire, offered to a church that called itself rich.
The Voices
With the work named.
Adam Clarke knows the trade: the cupel, the lead, the moment the metal goes still, and the refiner sitting at his fire. Albert Barnes lays the four readings of Isaiah 48:10 side by side and finds the workshop behind “a furnace of earth”. Jamieson, Fausset and Brown give the smelting pit its dimensions and split furnace from iron in five words.
John Gill notices that the four men in the fire are loose. Athanasius, writing to churches under pressure, says the saints did not shrink from the fire because they knew what it was for. Gregory the Great supplies the page’s best single line. Oecumenius, in the sixth century, already reads Revelation’s gold through Psalm 12’s silver.
Where to Go Next
Where the fire is the whole scene
What the fire is working on
Where the picture goes on
Its neighbours in the index
The Symbolism of Scripture gathers every picture the Bible thinks in. This one sits with: