V. He constitutes the prophet a judge over this people that now stand upon their trial: as ch. i. 10, I have set thee over the nations; so here, I have set thee for a tower, or as a sentinel, or a watchman, upon a tower, among my people, as an inspector of their actions, that thou mayest know, and try their way, v. 27. Not that God needed any to inform him concerning them; on the contrary, the prophet knew little of them in comparison but by the spirit of prophecy. But thus God appeals to the prophet himself, and his own observation concerning their character, that he might be fully satisfied in the equity of God's proceedings against them and with the more assurance give them warning of the judgments coming. God set him for a tower, conspicuous to all and attacked by many, but made him a fortress, a strong tower, gave him courage to stem the tide and bear the shock of their displeasure. Those that will be faithful reprovers have need to be firm as fortresses. Now in trying their way he will find two things:—1. That they are wretchedly debauched (v. 28): They are all grievous revolters, revolters of revolters (so the word is), the worst of revolters, as a servant of servants is the meanest servant. They have a revolting heart, have deeply revolted, and revolt more and more. They seemed to start fair, but they revolt and start back. They walk with slanders; they make nothing of belying and backbiting one another, nay, they make a perfect trade of it; it is their constant course, and they govern themselves by the slanders they hear, hating those that they hear ill-spoken of, though ever so unjustly. They are brass and iron, base metals, and there is nothing in them that is valuable. They were as silver and gold, but they have degenerated. Nay, as they are all revolters, so they are all corrupters, not only debauched themselves, but industrious to debauch others, to corrupt them as they themselves are corrupt; nay, to make them seven times more the children of hell than themselves. It is often so; sinners soon become tempters. 2. That they would never be reclaimed and reformed; it was in vain to think of reforming them, for various methods had been tried with them, and all to no purpose, v. 29, 30. He compares them to ore that was supposed to have some good metal in it, and was therefore put into the furnace by the refiner, who used all his art, and took abundance of pains, about it, but it proved all dross, nothing of any value could be extracted out of it. God by his prophets and by his providences had used the most proper means to refine this people and to purify them from their wickedness; but it was all in vain. By the continual preaching of the word, and in a series of afflictions, they had been kept in a constant fire, but all to no purpose. The bellows have been still kept so near the fire, to blow it, that they are burnt with the heat of it, or they are quite worn out with long use and thrown into the fire as good for nothing. The prophets have preached their throats sore with crying aloud against the sins of Israel, and yet they are not convinced and humbled. The lead, which was then used in refining silver, as quicksilver is now, is consumed of the fire, and has not done its work. The founder melts in vain; his labour is lost, for the wicked are not plucked away, no care is taken to separate between the precious and the vile, to purge out the old leaven, to cast out of communion those who, being corrupt themselves, are in danger of infecting others. Or, Their wickednesses are not removed (so some read it); they are still as bad as ever, and nothing will prevail to part between them and their sins. They will not be brought off from their idolatries and immoralities by all they have heard, and all they have felt, of the wrath of God against them; and therefore that doom is passed upon them (v. 30): Reprobate silver shall they be called, useless and worthless; they glitter as if they had some silver in them, but there is nothing of real virtue or goodness to be found among them; and for this reason the Lord has rejected them. He will no more own them as his people, nor look for any good from them; he will take them away like dross (Ps. cxix. 119), and prepare a consuming fire for those that would not be purified by a refining fire. By this it appears, (1.) That God has no pleasure in the death and ruin of sinners, for he tries all ways and methods with them to prevent their destruction and qualify them for salvation. Both his ordinances and his providences have a tendency this way, to part between them and their sins; and yet with many it is all lost labour. We have piped unto you, and you have not danced; we have mourned unto you, and you have not wept. Therefore, (2.) God will be justified in the death of sinners and all the blame will lie upon themselves. He did not reject them till he had used all proper means to reform them; did not cast them off so long as there was any hope of them, nor abandon them as dross till it appeared that they were reprobate silver.