II. How the woeful destruction of this degenerate house of Israel is foretold. They are all gathered together in Jerusalem; thither people fled from all parts of the country as to a city of refuge, not only because it was a strong city, but because it was the holy city. Now God tells them that their flocking into Jerusalem, which they intended for their security, should be as the gathering of various sorts of metal into the furnace or crucible, to be melted down, and to have the dross separated from them. They are in the midst of Jerusalem, surrounded by the forces of the enemy; and, being thus enclosed, 1. The fire of God's wrath shall be kindled upon this furnace, and it shall be blown, to make it burn fiercely and strongly, v. 20, 21. God will gather them in his anger and fury. The blowing of the fire makes a great noise, so will the judgments of God upon Jerusalem. When God stirs up himself to execute judgments upon a provoking people, from the consideration of his own glory and the necessity of making some examples, then he may be said to blow the fire of his wrath against sin and sinners, to heat the furnace seven times hotter. 2. The several sorts of metal gathered in it shall be melted; by a complication of judgments, as by a raging fire, their constitution shall be dissolved, they shall lose all their former shape and strength, and shall be utterly unable to stand before the wrath of God. The various sorts of sinners shall be melted down together, and united in a common overthrow, as brass and lead in the same furnace, as trees are bound in bundles for the fire. They came together into Jerusalem as a place of defence, but God brought them together there as unto a place of execution. 3. God will leave them in the furnace (v. 20): I will gather you into the furnace and will leave you there. When God brings his own people into the furnace he sits by them, as the refiner by his gold, to see that they be not continued there any longer than is fitting and needful; but he will bring these people into the furnace, as men throw dross into it, which they design shall be consumed, and therefore are in no care about it, but leave it there. Compare with this Hos. v. 14, I will tear and go away. 4. Hereby the dross shall be wholly separated and the good metal purified, the impenitent shall be destroyed and the penitent reformed and fitted for deliverance. Take away the dross from the silver, and there shall come forth a vessel for the finer, Prov. xxv. 4. This judgment shall do that in the house of Israel for the doing of which other methods had been tried in vain, and reprobate silver shall they no more be called, Jer. vi. 30.