For wickedness burneth as the fire. The Prophet attacks the wicked, who are accustomed to defend themselves by laying the blame on God. Either they practice evasions, in order to convince themselves that they are innocent, or, when they have been convicted, they still extenuate their guilt, as if the severity of God were beyond proper bounds. Never, certainly, do they acknowledge that God is just in punishing them, till they are compelled to acknowledge it; and even though they do not venture to excuse themselves publicly, still they fret and murmur. With the view of repressing such insolence, the Prophet compares the calamities to burning, but shows that the wickedness of men is the wood and fuel, by which the anger of God is kindled: as if he had said, "All exclaim and make loud complaints that the wrath of God burns violently, and yet they do not consider that their own sins are the fans by which it is inflamed, and that those sins supply the fuel, and that even themselves are consumed by the inward fire of their crimes." It shall devour the briers and thorns. The meaning is, that this flame will seize every part of Judea. Two things are here expressed, that the punishment of sin proceeds from the judgment of God, and yet that the blame lies with the sinners themselves, that they may not remonstrate with God as if he had dealt cruelly with them. There is a beautiful gradation; for we perceive that it usually happens that a fire, kindled in the lowest part of any place, gathers strength by degrees, spreads wider and wider, and ascends to the higher parts. Such will the wrath of God be; for Isaiah shows that it does not all at once seize the wicked, but is gradually kindled, till it utterly destroy them. At first the Lord proceeds gently, but if a light chastisement produce no good effect, he increases and doubles the punishment. If he see that we are obstinate, his wrath burns to the uttermost, so as to destroy us altogether, and consume us like a thick forest. Lastly, as the Prophets elsewhere declare, we must be like chaff and straw as soon as the wrath of God is kindled. (Psalm 83:14; Isaiah 5:24; 33:11; 40:24; 41:2; 47:14)

For wickedness - This commences the third part of the prophecy, which continues to the end of the chapter. It is a description of prevailing impiety. The effects and prevalence of it are described by the image of a raging, burning flame, that spreads everywhere: first among the humble shrubbery - the briers and thorns, then in the vast forests, until it spreads over the land, and sends a mighty column of flame and smoke up to heaven.
Burneth as the fire - Spreads, rages. extends as fire does in thorns and in forests. In what respects it burns like the fire, the prophet immediately specifies. It spreads rapidly everywhere, and involves all in the effects. Wickedness is not unfrequently in the Scriptures compared to a fire that is shut up long, and then bursts forth with raging violence. Thus Hosea 7:6 :
Truly, in the inmost part of it, their heart is like an oven,
While they lie in wait;
All the night their baker sleepeth;
In the morning it burneth like a blazing star.
'As an oven conceals the lighted fire all night, while the baker takes his rest, and in the morning vomits forth its blazing flame; so all manner of concupiscence is brooding mischief in their hearts, while the ruling faculties of reason and conscience are lulled asleep, and their wicked designs wait only for a fair occasion to break forth.' - Horsely on Hosea; see also Isaiah 50:2; Isaiah 65:5.
It shall devour - Hebrew, 'It shall eat.' The idea of devouring or eating, is one which is often given to fire in the Scriptures.
The briers and thorns - By the briers and thorns are meant, doubtless, the lower part of the population; the most degraded ranks of society. The idea here seems to be, first, that of impiety spreading like fire over all classes of people; but there is also joined with it, in the mind of the prophet, the idea of punishment. Wickedness would rage like spreading fire; but like fire, also, it would sweep over the nation accomplishing desolation and calamity, and consuming everything in the fire oft God's vengeance. The wicked are often compared to thorns and briers - fit objects to be burned up; Isaiah 33:12 :
And the people shall be as the burnings of lime;
As thorns cut up shall they be burned in the fire.
And shall kindle - Shall burn, or extend, as sweeping fire extends to the mighty forest.
In the thickets of the forests - The dense, close forest or grove. The idea is, that it extends to all classes of people - high as well as low.
And they shall mount up - The Hebrew word used here - יתאבכוּ yit'abekû from אבך 'âbak - occurs nowhere else. The image is that of a far-spreading, raging fire, sending columns of smoke to heaven. So, says the prophet, is the rolling, raging, consuming fire of the sins of the nation spreading over all classes of people in the land, and involving all in widespread desolation.

For wickedness - Wickedness rageth like a fire, destroying and laying waste the nation: but it shall be its own destruction, by bringing down the fire of God's wrath, which shall burn up the briers and the thorns; that is, the wicked themselves. Briers and thorns are an image frequently applied in Scripture, when set on fire, to the rage of the wicked; violent, yet impotent, and of no long continuance. "They are extinct as the fire of thorns," Psalm 118:12. To the wicked themselves, as useless and unprofitable, proper objects of God's wrath, to be burned up, or driven away by the wind. "As thorns cut up they shall be consumed in the fire," Isaiah 33:12. Both these ideas seem to be joined in Psalm 58:9 : -
"Before your pots shall feel the thorn,
As well the green as the dry, the tempest shall bear them away."
The green and the dry is a proverbial expression, meaning all sorts of them, good and bad, great and small, etc. So Ezekiel: "Behold, I will kindle a fire, and it shall devour every green tree, and every dry tree," Ezekiel 20:47. D'Herbelot quotes a Persian poet describing a pestilence under the image of a conflagration: "This was a lightning that, falling upon a forest, consumed there the green wood with the dry." See Harmer's Observations, Vol. II., p. 187.

For wickedness (p) burneth as the fire: it shall devour the briers and thorns, and shall kindle in the thickets of the forest, and they shall mount up [like] the rising of smoke.
(b) Wickedness as a bellows kindles the fire of God's wrath which consumes all his obstinate enemies.

For wickedness burneth as the fire,.... That is, the punishment of their sins, as the Targum interprets it; the wrath of God for sin, which is poured out like fire, and consumes as that does; unless wicked men are meant, who are consumed with the fire of divine vengeance; the sense is the same:
it shall devour the briers and thorns; sinners and ungodly, so the Targum paraphrases it; and Aben Ezra observes, they are the wicked; who are compared to briers and thorns, for their unfruitfulness in themselves, harmfulness to others, and for their weakness to stand against the fury of incensed Deity, see 2-Samuel 23:6,
and shall kindle in the thickets of the forest. Kimchi thinks there is a gradation in these words, that as fire first begins to burn the thorns, and smaller wood, and then the greater; so wickedness consumes first the little ones, who are the thorns, and after that it kindles in the thickets of the forest, who are the great ones; so the commonwealth of Israel is compared to a forest; and the thorns, briers, and thickets, may denote the common people and their governors, who all being guilty of wickedness, should not escape the vengeance of God:
and they shall mount up like the lifting up of smoke: or lift up themselves, or be lifted up; so Aben Ezra and Kimchi interpret the word; but Jarchi thinks it has the signification of "to be perplexed": and gives the sense of it thus; they are perplexed, and shut up with the strength of smoke that burns: others take it to be a word of the same meaning with and render it, "they shall pulverize", or "go into dust in the lifting up of smoke" (d); and denotes the dissolution of the commonwealth; but perhaps it may be better rendered, "though they shall walk proudly" (or behave haughtily), their "pride" shall be as "smoke", which soon vanishes away; since the word, which is only here used, in the Syriac language signifies to walk proudly, as a cock with two crests (e).
(d) "et epulverabitur erectione fumi", Cocceius; "adeo ut in minutissimum pulverem abeant elato fumo, vel elatione fumi", Junius & Tremellius, Piscator. (e) "Et superbient, (fastuose se gerent,) at superbia (vel quorum superbia) fumus, h. e. fumi instar, evanescit, interibit, quod etiam Armenis indigiat, isfud vacobulum `Abac', Syr. galus, gallinaceus, superbo gradu incedens et bicristatus", Castel. Lexicon Polyglott. col. 12.

Third strophe.
burneth--maketh consumption, not only spreading rapidly, but also consuming like fire: sin is its own punishment.
briers . . . thorns--emblem of the wicked; especially those of low rank (Isaiah 27:4; 2-Samuel 23:6).
forest--from the humble shrubbery the flame spreads to the vast forest; it reaches the high, as well as the low.
mount up like . . . smoke--rather. "They (the thickets of the forest) shall lift themselves proudly aloft [the Hebrew is from a Syriac root, a cock, expressing stateliness of motion, from his strutting gait, HORSLEY], in (in passing into) volumes of ascending smoke" [MAURER].

Strophe 3. "For the wickedness burneth up like fire: it devours thorns and thistles, and burns in the thickets of the wood; and they smoke upwards in a lofty volume of smoke. Through the wrath of Jehovah of hosts the land is turned into coal, and the nation has become like the food of fire: not one spares his brother. They hew on the right, and are hungry; and devour on the left, and are not satisfied: they devour the flesh of their own arm: Manasseh, Ephraim; and Ephraim, Manasseh: these together over Judah. With all this His anger is not turned away, and His hand is stretched out still." The standpoint of the prophet is at the extreme end of the course of judgment, and from that he looks back. Consequently this link of the chain is also past in his view, and hence the future conversives. The curse, which the apostasy of Israel carries within itself, now breaks fully out. Wickedness, i.e., the constant thirst of evil, is a fire which a man kindles in himself. And when the grace of God, which damps and restrains this fire, is all over, it is sure to burst forth: the wickedness bursts forth like fire (the verb is used here, as in Isaiah 30:27, with reference to the wrath of God). And this is the case with the wickedness of Israel, which now consumes first of all thorns and thistles, i.e., individual sinners who are the most ripe for judgment, upon whom the judgment commences, and then the thicket of the wood (sib-che,
(Note: The metheg (gaya) in סבכי (to be pronounced sib-che) has simply the caphonic effect of securing a distinct enunciation to the sibilant letter (in other instances to the guttural, vid., ‛arboth, Numbers 31:12), in cases where the second syllable of the word commences with a guttural or labial letter, or with an aspirate.)
as in Isaiah 10:34, from sebac, Genesis 22:13 = sobec), that is to say, the great mass of the people, which is woven together by bands of iniquity (vattizzath is not a reflective niphal, as in 2-Kings 22:13, but kal, to kindle into anything, i.e., to set it on fire). The contrast intended in the two figures is consequently not the high and low (Ewald), nor the useless and useful (Drechsler), but individuals and the whole (Vitringa). The fire, into which the wickedness bursts out, seizes individuals first of all; and then, like a forest fire, it seizes upon the nation at large in all its ranks and members, who "whirl up (roll up) ascending of smoke," i.e., who roll up in the form of ascending smoke (hith'abbek, a synonym of hithhappēk, Judges 7:13, to curl or roll). This fire of wickedness was no other than the wrath (ebrâh) of God: it is God's own wrath, for all sin carries this within itself as its own self-punishment. By this fire of wrath the soil of the land is gradually but thoroughly burnt out, and the people of the land utterly consumed: עתם ἁπ λεγ to be red-hot (lxx συγκέκαυται, also the Targum), and to be dark or black (Arabic ‛atame, late at night), for what is burnt out becomes black. Fire and darkness are therefore correlative terms throughout the whole of the Scriptures. So far do the figures extend, in which the prophet presents the inmost essence of this stage of judgment. In its historical manifestation it consisted in the most inhuman self-destruction during an anarchical civil war. Destitute of any tender emotions, they devoured one another without being satisfied: gâzar, to cut, to hew (hence the Arabic for a butcher): zero'o, his arm, according to Jeremiah 19:9, equivalent to the member of his own family and tribe, who was figuratively called his arm (Arabic ‛adud: see Ges. Thes. p. 433), as being the natural protector and support. This interminable self-immolation, and the regicide associated with the jealousy of the different tribes, shook the northern kingdom again and again to its utter destruction. And the readiness with which the unbrotherly feelings of the northern tribes towards one another could turn into combined hostility towards Judah, was evident enough from the Syro-Ephraimitish war, the consequences of which had not passed away at the time when these prophecies were uttered. This hostility on the part of the brother kingdoms would still further increase. And the end of the judgments of wrath had not come yet.

Burneth - Shall burn you, as it follows, shall devour. Thorns - The low and mean persons; for these are opposed to the thickets of the forest, in the next clause. Forest - In the wood, where the trees are tall, and stand thick, having their bows entangled together, which makes them more ready both to catch and to spread the fire. Smoak - Sending up smoak like a vast furnace.