John Gill's Exposition of the Whole Bible
Isaiah 1:25
And I will turn my hand upon thee,.... The remnant, according to the election of grace, left in Jerusalem, Isaiah 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 Isaiah 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 Zechariah 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, Philippians 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, Psalms 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.