Jerome : (Verse 25) And I will turn my hand against you; and I will thoroughly purge away your dross and take away all your alloy. Regarding the dross, which Symmachus interpreted as 'στέμφυλα' (clusters of grapes), Aquila as 'γιγαρτῶδες' (bunch of grapes), and Theodotion as 'acinum uvae' (grape kernel), the Septuagint alone, translating more the sense than the words, understood it as 'unbelievers' or 'disobedient ones'. For after he had said, 'Your silver has become dross,' he now uses a metaphor, that he may stretch out his hand over it, that is, extend his hand for punishment and cleansing, and purge away all the filth and vices of sins, so that, the alloy being separated, pure silver may remain, which cannot be made without fire, through which he signifies that they will suffer torments. We also read in Malachi about the Lord: He will come forth like a flame of a smelting furnace, and like the herb of the fullers, and He will sit refining and purifying like silver and gold; and He will purify the sons of Levi (Malachi 3:2-3), so that after they have been cleansed, it may be said of them: And they shall be the Lord's offering in righteousness. Ezekiel also says that the whole house of Israel is mixed with brass, iron, lead, and tin, and needs to be purified; so that after it has been purified, it may recognize that He is the Lord (Ezekiel 22:18). But also in the Gospel under another metaphor the same meaning is shown: Whose fan is in his hand, and he will thoroughly cleanse his floor and gather his wheat into the barn; but the chaff he will burn with unquenchable fire. (Matthew 3:12). (Verse 26.) And I will restore your judges as at the first, and your counselors as at the beginning. Afterward you shall be called the city of righteousness, the faithful city. Zion shall be redeemed with justice, and her penitents with righteousness. But rebels and sinners shall be broken together, and those who forsake the Lord shall be consumed. For they shall be ashamed of the oaks that you desired, and you shall blush for the gardens that you have chosen. For you shall be like an oak whose leaf withers, and like a garden without water. And the strong shall become tinder, and his work a spark, and both of them shall burn together, with none to quench them. Your chosen trees shall become fuel for the fire, and the people shall labor in vain, and the nations shall weary themselves for nothing. The Lord's hand shall be raised against Mount Zion, and he will lay it waste; its fields shall become a desolation, and its cities a ruin. Then will the Lord cause his majestic voice to be heard and the descending blow of his arm to be seen, in furious anger and a flame of devouring fire, with a cloudburst and storm and hailstones. The Assyrians will be terror-stricken at the voice of the Lord, when he strikes with his rod. And every stroke of the appointed staff that the Lord lays on them will be to the sound of tambourines and lyres. Battling with brandished arm, he will fight with them. For a burning place has long been prepared; indeed, for the king it is made ready, its pyre made deep and wide, with fire and wood in abundance; the breath of the Lord, like a stream of sulfur, kindles it. Therefore, it will restore the likeness of the Judges: either after the Babylonian captivity, as the Jews desire, Zerubbabel, Ezra, Nehemiah, and the other leaders who governed the people until Hircanus, whom Herod succeeded in the kingdom; or certainly, more truly and rightly, the Apostles, and those who believed through the Apostles, and were established as leaders of the Church, as we have said at the beginning of this vision, that both the warning and the promise pertain to the time of the Lord's passion, and to the faith which he founded the Church after his passion. After this you shall be called the city of the just, the faithful city. These things clearly pertain to the Church, which will believe in the Lord, both concerning the Jews and the Gentiles, as the prophetic word includes. However, the city of the just, that is, of the Lord Savior, shall also be called just, of which it is said: A city set on a mountain cannot be hidden (Matt. 5:14). Calling it faithful, he also indicates that it should be called a metropolis according to the Septuagint, by those who will believe in the Lord. — Commentary on Isaiah John Cassian : This occurs for the sake of cleansing, however, when he humbles his righteous ones for their small and as it were insignificant sins or because of their proud purity, giving them over to various trials in order to purge away now all the unclean thoughts … which he sees have collected in their inmost being, and in order to submit them like pure gold to the judgment to come, permitting nothing to remain in them that the searching fire of judgment might afterwards find to purge with penal torment. — CONFERENCE 6:11.2 John Chrysostom : "For we are not as the rest, which corrupt the word of God." `For even if we use great sounding words, yet we declared nothing to be our own that we achieved, but all Christ's. For we will not imitate the false apostles; the men who say that most is of themselves.' For this is "to corrupt," when one adulterates the wine; when one sells for money what he ought to give freely. For he seems to me to be here both taunting them in respect to money, and again hinting at the very thing I have said, as that they mingle their own things with God's; which is the charge Isaiah brings when he said, "Thy vintners mingle wine with water:" for even if this was said of wine, yet one would not err in expounding it of doctrine too. `But we,' saith he, `do not so: but such as we have been entrusted with, such do we offer you, pouring out the word undiluted.' — HOMILIES ON 2 Corinthians 5:3