The interpretation timeline
Isaiah 1:25 Douay-Rheims

And I will turn my hand to thee, and I will clean purge away thy dress, and I will take away all thy tin.

A.D. 407 – 1875 9 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“For we will not mimic the false prophets who say that most things have been done by them. This is the meaning of "to corrupt," when someone dilutes the wine, or when someone sells something which ought to be given away freely. He seems to me to be both taunting them regarding money and hinting at the fact that they have mingled the things of God with their own things, as I have said. This is the accusation of Isaiah, who says, "Your wine merchants mingle wine with water." Even if this statement were about wine, one would not sin to say it of doctrine as well. He says, "We do not do this, but we offer to you what we have been given, pouring out the undiluted word."”
Source
435
A.D.
John Cassian Patristic
c. A.D. 360–435
“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.”
Source

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“And I will return My hand upon you One blow after another, until the transgressors have been completely destroyed. as with lye This is an expression meaning soap [sbon in O.F., savon (in modern French)]. Its deviation is an expression of cleanliness, similar to (Ps. 24:4): “and pure (בַּר) of heart,” since it cleanses the garment of its stains. your dross mentioned above, as: “Your silver has become dross”; a mixture of silver with copper is called dross. Here too, a mixture of the wicked with the righteous. I will destroy the transgressors, who are all dross. all your tin The tin mixed with silver, that is to say, the wicked among you. בְדִיל is called estejjn [etain] in O.F. [tin].”
Source
1167
A.D.
Ibn Ezra Jewish
1089–1167
“ידי My hand; that is, my smiting (comp. Exod. 9:3). כבור As if it were with soap ; = בור בורית ‘ soap ’; or more correctly, purely (comp. Ps. 18:25). Thy dross. This expression reverts to the former metaphor, thy silver is become dross. בדיליך Thy tin. R. Moses Hakkohen remarks, that the names of the seven kinds of metal are not found in the Bible in the plural ; he forgets בדיליך, which is plural; the singular would be בדילֵך . היחידים, two exceptions: בדיליך ‘thy tin,’ and כספיהם ‘their silver’ (Gen. 42:25). R. Moses Hakkohen does not say the seven kinds of metal, but ועפרת זהב וכסף ונחשת וברזל ובדיל Gold, silver, brass, iron, tin, lead. I. E. makes seven out of these six by applying כסף to silver and mercury (כסף חי)”
Source
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“How is she become a harlot. Here he shows their sin according to the turning away from justice toward one's neighbor: and concerning this he does three things. First he describes the fault; second he threatens the punishment, at the place, Therefore thus saith the Lord; third, the sequel of the punishment, at the place, And I will restore. Concerning the first, first he reproves the sin of the people; second, the sin of the priest, at thy silver; third, the sin of the prince, at thy princes. In the people he reproves two things, aggravating by comparison to their former state: namely, venality by comparison to their former fidelity: whence, how is she become a harlot? Jer. 2: under every leafy tree and upon every high hill thou didst lie down, a harlot: and cruelty by comparison to justice and judgment, which is the execution of justice. Ps. 93: until justice be turned into judgment. Whence he says: but now murderers. Hosea 4: cursing and lying and killing and theft and adultery have overflowed, and blood hath touched blood. The sin of the priest he reproves in two things. In the corruption of the truth of doctrine: whence he says: thy silver is turned into dross. Ps. 11: the words of the Lord are pure words, silver tried by the fire, proved from the earth, refined seven times. Jer. 5: the prophets have prophesied a lie. Second, in the remission of the severity of discipline, which is signified in the wine: for this is the wine which the Samaritan poured in: Luke 10. Whence he says: thy wine. Ezech. 13: woe to them that sew. Thy princes. Here he reproves the sin of the princes: and first he shows them unfaithful in the execution of their office, in that they carry it out for their own advantage and not that of the people. Amos 6: anointed with the best ointment, drinking wine in bowls. Ezech. 34: woe to the shepherds of Israel, that feed themselves. Should not the flocks be fed by the shepherds? And for this he says, faithless. Second he shows them transgressors in the harboring of evildoers: companions of thieves, by defending them and affording them patronage: Hosea 6: as the throats of robber men, the princes of the priests. Prov. 1: son, walk not with them. Third he shows them corrupted in the receiving of gifts. Below, 5: Woe to you that justify the wicked for gifts, and take away the justice of the just from him. Whence he says: they love gifts — received ones; they follow after — things promised or hoped for. Fourth, he shows them unjust in the repulsion of the poor, saying they judge not for the fatherless. Jer. 5: they have not judged the cause of the widow, they have not directed the cause of the fatherless. Therefore thus saith the Lord. Here he threatens the punishment: and first, of the prelates; second, of the subjects, at and I will turn. Concerning the first he sets down three things. First, the power of the one punishing, in authority, saying, the Lord. Malachi 1: if I be the Lord, where is my fear? saith the Lord. In the multitude of ministers: of hosts. Job 25: is there any numbering of his soldiers? In strength, mighty. Job 9: he is wise in heart and mighty in strength: who hath resisted him, and hath had peace? Second he sets down the will of the one punishing. Ah, namely to them, I will comfort myself, since their punishment will be a consolation. Below, 63: the day of vengeance is in my heart, the year of my recompense is come. Third he sets down the cruelty of the punishment: at and I will take vengeance on my enemies: as if to say: I will punish you as enemies. Deut. 32: I will render vengeance to my enemies, and repay them that hate me. And I will turn. Here he threatens the punishment of the subjects. And first is set down the preparation of the one punishing, at and I will turn my hand upon thee to punish thee, which, in sparing, I had held as it were folded up. Job 19: the hand of the Lord hath touched me. Second, the completion of the punishment: I will melt away, by the fire of tribulation, to the pure, until whatever is to be purged is purged. Matt. 5: thou shalt not go out from thence till thou repay the last farthing. Third, the multitude of punishments: I will take away all thy tin: because for every sin, below, 40: she hath received of the hand of the Lord double for all her sins. And I will restore. Here he sets down the sequel of the punishment: and first, as regards those corrected, renewal; second, as regards the obstinate, consumption, at and he shall crush. For by the same fire (as Augustine says) gold is proved, and straw smokes. Concerning the first he does three things. First he promises renewal as regards the amendment of the prelates; second, as regards the restoration of good name, at after this thou shalt be called; third, as regards the observance of justice, at Zion in judgment. He says therefore: I will restore the judges, as regards the secular princes, whose office it is to judge the people, and thy counsellors, that is, the priests, whose office it is to minister the counsels of God to the peoples: Malachi 2: the lips of the priests keep knowledge, and they seek the law at his mouth: because he is the angel of the Lord of hosts: as they were before, as Moses and Joshua, who pleased God. Jer. 3: I will give you pastors according to my own heart, and they shall feed you with knowledge and doctrine. And thou shalt be called, that is, thou shalt recover thy fame, so that thou art called such as thou wast before, the city of the just, that is, in which justice is kept. Below, 62: thou shalt no more be called Forsaken, neither shalt thou any more be called Desolate; but thou shalt be called My will is in her. Zion in judgment, through the execution of justice, shall be redeemed, from those who wrong her; and they shall bring her back in justice; for judgment is to bring back to equality, in which justice consists. Ps. 71: to judge thy people with justice, and thy poor with judgment. Jer. 23: a king shall reign (...) and shall do justice and judgment in the land. And he shall crush. Here is set down the destruction of the obstinate; and concerning this he does three things. First he foretells the destruction; second, the manner of the destruction, at they shall be confounded; third, he takes away the hope of escape, at and thy strength shall be. And since the punishment is ordered against the fault, therefore concerning the first he touches on the fault in two ways. On the part of turning, as regards the crime of idolatry: whence he says, the wicked; and as regards the sin of pleasure and luxury: whence he says, sinners: because men are most prone to such things; against which he ordains the punishment of crushing, wherein a punishment is marked out to match the wrong inflicted. Jer. 17: crush them with a double destruction; as it were for a double sin. Second, on the part of turning away, because they have forsaken the Lord; against which he ordains the punishment of consumption, saying, they shall be consumed; in which he designates the punishment of desertion: for what is consumed goes into nothing, and all things would fall into nothing, unless the hand of the Lord held them together; as Gregory says. Jer. 17: O Lord, all that forsake thee shall be confounded: they that depart from thee shall be written in the earth: because they have forsaken the vein of living waters, the Lord. They shall be confounded. Here he sets down the manner of the destruction: and first, as regards the confusion of sin; second, as regards the taking away of good, at when you shall be. Concerning the first, against idolatry he ordains confusion, saying: they shall be confounded for the idols, that is, on account of the idols. Ps. 96: let them all be confounded that adore graven things: against pleasure, shame, when he says: you shall be ashamed of the gardens, that is, of the pleasurable places, which you had chosen, of your luxury. Rom. 6: what fruit had you in those things, of which you are now ashamed? For confusion regards more the evil; but shame regards the fault. For carnal sins (as Gregory says) are of lesser fault and greater infamy. And the reason is, that they are according to the baser powers, and most material ones: and yet they are innate and connatural and subject to passion. When you shall be. Here is set down the taking away of good: and first, of that which pertains to protection and adornment, which is signified in the taking away of leaves; second, of that which pertains to fruit, at as a garden without water, barren. And in contrast it is said of the just man, Ps. 1: he shall be as a tree which is planted near the running waters. And it shall be. Here he takes away from them the hope of escape: and he sets down three things. First he takes away from them the support of their own strength: whence he says: thy strength shall be as the ash of tow, which is quickly consumed. Ecclus. 21: the congregation of sinners is like tow heaped together. Second, the help of idols, saying: your work, namely of idols, which your hands have wrought, as a spark, which is of no consequence. Deut. 32: where are their gods, in whom they trusted? And yet it is burnt up: whence follows, and it shall be kindled. Below, 50: walk in the light of your fire. Third, the help of men: and there shall be none to quench it. Ezech. 20: the flame of the kindling shall not be quenched, and every face shall be burnt in it, from the south even to the north; and all flesh shall see.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And I will turn my hand upon thee,.... The remnant, according to the election of grace, left in Jerusalem, Isa 1:9 meaning not his afflicting hand, no, not even as a fatherly chastisement; though the Lord sometimes, by such means, purges away the iniquity of his people, as follows; see Isa 27:9 much less his hand of wrath and vengeance, the lighting down of his arm, with the indignation of his anger; but his hand of efficacious grace in conversion, with which he plucks sinners as brands out of the burning; delivers them from the power of Satan; turns their hearts to himself; opens them, to attend unto and understand divine things; breaks them in pieces with the hammer of his word; works grace in them, and carries on the good work in their souls: all which is owing to his mighty hand of grace upon them, and to the exertions of the exceeding greatness of his power towards them. This was accomplished in part in the conversion of a large number of the Jews on the day of Pentecost, and afterwards; and will be more fully accomplished in the latter day, when that people shall turn to the Lord, in consequence of his hand of powerful grace being turned on them. The phrase is used of the display of divine grace and mercy, in Zac 13:7. and purely purge away thy dross; which the Targum rightly interprets of "ungodliness" or wickedness; it means the sins of converted ones, which, at conversion, they are purely purged from; not that sin, as to the being of it, is removed from them; that dwells in them, abides with them; and, like dross, is a heavy burden, a dead weight upon them, and will be while they are in this tabernacle, and makes them groan, being burdened; so far from it, that in their view it rather increases; they see the plague of their own hearts; and such innumerable swarms of corruption they never saw before; sin revives, and they die; but in conversion grace superabounds it, deluges over it, keeps down the force and power of it, so that it has not the dominion; the old man is put off concerning the former conversation, which ceases to be a series, a course of sinning: besides, through the sprinkling of the blood of Christ, which cleanseth from all the dross and filth of sin, the guilt is removed from the conscience, and perfect peace and full pardon take place; all iniquity is caused to pass from them, and they are clothed with change of raiment, the righteousness of Christ, by which they are justified from all things, and are pure, spotless, and without fault before the throne: and take away all thy tin. The Targum also interprets this of iniquity, rendering it, "I will take away all thy sin"; but it is better to understand it of self-righteousness; which, as tin is of more worth than dross, and looks like silver; so this has the appearance of some good in it, and was what the Jews were fond of, trusted in, and depended on, and which they followed after, and endeavoured to establish and hold fast; but this in conversion is all taken away: the Lord, by his Spirit; convinces of the weakness and insufficiency of it, to justify in his sight; shows that it is not a righteousness, and will be of no service in that respect; yea, takes away these filthy rags, and clothes with the righteousness of Christ; causes the soul to drop and renounce its own righteousness, and put on that; and not only to renounce works before conversion, but all after it, as a profession of religion, subjection to Gospel ordinances, and all works, though done in faith, and in a right manner; a glaring instance we have of all this in one of that little remnant, the Apostle Paul, Phi 3:6. Moreover, by "dross" and "tin", or "tins", in the plural number, may be meant persons; wicked and profane men, by the former, who should be put away like dross, Psa 119:119 and self righteous persons, by the latter; who shine like silver, make a show of religion, appear outwardly righteous; but these, as well as the other, should be separated from the people of God, when the precious and the vile should be distinguished.”
Source
1849
A.D.
1774–1849
“Tin. I will reform abuses in the reign of Ezechias, but much more by establishing the Church of Christ, which shall be the faithful city. (Calmet)”
1871
A.D.
1871
“turn . . . hand--not in wrath, but in grace (Zac 13:7), "upon thee," as Isa 1:26-27 show; contrasted with the enemies, of whom He will avenge Himself (Isa 1:24). purely--literally, "as alkali purifies." thy dross--not thy sins, but the sinful persons (Jer 6:29); "enemies" (Isa 1:24); degenerate princes (see on Isa 1:22), intermingled with the elect "remnant" of grace. tin--Hebrew, bedil, here the alloy of lead, tin, &c., separated by smelting from the silver. The pious Bishop Bedell took his motto from this.”
Source
1875
A.D.
Keil & Delitzsch Lutheran
1861–1875
“Isa 1:25 states clearly in what the revenge consisted with which Jehovah was inwardly burdened (innakmah, a cohortative with the ah, indicating internal oppression): "And I will bring my hand over thee, and will smelt out thy dross as with alkali, and will clear away all thy lead." As long as God leaves a person's actions or sufferings alone, His hand, i.e., His acting, is at rest. Bringing the hand over a person signifies a movement of the hand, which has been hitherto at rest, either for the purpose of inflicting judicial punishment upon the person named (Amo 1:8; Jer 6:9; Eze 38:12; Psa 81:15), or else, though this is seldom the case, for the purpose of saving him (Zac 13:7). The reference here is to the divine treatment of Jerusalem, in which punishment and salvation were combined - punishment as the means, salvation as the end. The interposition of Jehovah was, as it were, a smelting, which would sweep away, not indeed Jerusalem itself, but the ungodly in Jerusalem. They are compared to dross, or (as the verb seems to imply) to ore mixed with dross, and, inasmuch as lead is thrown off in the smelting of silver, to such ingredients of lead as Jehovah would speedily and thoroughly remove, "like alkali," i.e., "as if with alkali" (Cabbor, Comparatio decurtata, for C'babbor: for this mode of dropping Beth after Caph, compare Isa 9:3; Lev 22:13, and many other passages). By bedilim (from bâdal, to separate) we are to understand the several pieces of stannum or lead (Note: Plumbum nigrum, says Pliny, n. n. xxiv. 16, is sometimes found alone, and sometimes mixed with silver: ejus qui primus fluic in fornacibus liquor, stannum appellatur. The reference here is to the lead separated from the ore in the process of obtaining pure silver. In the form of powder this dross is called bedil, and the pieces bedilim; whereas ophereth is the name of solid lead, obtained by simply melting down from ore which does not contain silver. The fact that bedil is also apparently used as a name for tin, may be explained in the same way as the homonymy of iron and basalt (Com. on Job 28:2), and of the oak and terebinth. The two metals are called by the same name on account of their having a certain outward resemblance, viz., in softness, pliability, colour, and specific gravity.) in which the silver is contained, and which are separated by smelting, all the baser metals being distinguished from the purer kinds by the fact that they are combustible (i.e., can be oxidized). Both bor, or potash (an alkali obtained from land-plants), and nether, natron (i.e., soda, or natron obtained from the ashes of marine plants, which is also met with in many mineral waters), have been employed from the very earliest times to accelerate the process of smelting, for the purpose of separating a metal from its ore.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.