Isaiah 1:16, 17.
Wash ye, make you clean, etc.
These words are supposed to express the power of man, and contradict the necessity of unfrustrable grace in conversion: the argument from them is formed in this manner; "If conversion be wrought only by the unfrustrable operation of God, and man is purely passive in it, vain are all these commands and exhortations directed to wicked men." The weakness of which conclusion will appear by considering particularly each command or exhortation.
1. Wash ye, make you clean; these two are to be regarded as one, since they intend one and the same thing; and suppose, that men, in a state of nature, are polluted and unclean; and indeed their pollution is of such sort, and to such a degree, that they cannot cleanse themselves, either by ceremonial ablutions, or moral services, or evangelical ordinances; for, who can say, I have made my heart clean; I am pure from my sin? (Prov. 20:9). This is God’s work only, as appears from his promises to cleanse his people from their sins; from the end of Christ’s shedding his blood, and the efficacy of it; from the sanctifying influences of the Spirit; and from the prayers of the saints (Ps. 51:2, 7, 10), to God, that he would create in them clean hearts, wash them thoroughly from their iniquity, and cleanse them from their sin. But if this be the case, that it is God’s work alone, and that man is incapable to cleanse himself from sin, it will be said, to what purpose are such exhortations? I answer, to convince men of their pollution, and that they stand in need of being washed and cleansed, of which they are naturally ignorant: there are two many who are pure in their own eyes, and yet not washed from their filthiness (Prov. 30:12); as also, to bring them to a sense of their own inability to cleanse themselves; which seems to be the particular design of them here; since these Jews thought to have washed themselves from their immoralities by their ceremonial services, and which are therefore rejected by God, verses 11-15; and they, notwithstanding all their legal purifications, are called upon to wash and make clean: besides, such exhortations may be useful to lead persons to inquire after the proper means of cleansing, and so to the fountain of Christ’s blood, in which only souls being washed are made clean. These exhortations then are not in vain; though conversion is wrought only by the unfrustrable operation of God, and man is purely passive in it. This view of them will help us to understand aright some parallel places; such as Jeremiah 4:14, 13:27; 2 Corinthians 7:1; James 1:21, and James 4:8, which commonly go in company with these.
2. Put away the evil of your doings from before mine eyes. Evil is said to be put away from a nation, when it is punished in the doer of it; see Deuteronomy 13:5, and Deuteronomy 17:7, 12; and from a family and particular persons, when discouraged and abstained from, Job 11:14, and 22:23. But it ought to be observed, that the exhortation here is not barely to put away their doings, but the evil of them; and that not from themselves, but from before the eyes of God. Now to put away sin in this sense, is to take it away, to remove it, as that it is pardoned, and men acquitted and discharged from it; but this is impracticable to men, and is the act of God only; as is evident from his promises to remove the sins of his people; from the end of Christ’s sacrifice which was to put away sin for ever; and from the prayers of the saints, who desire that God would take away all iniquity, and receive graciously. But why then is such an exhortation given? First to convince men, that the putting away of sin from the eyes of God’s vindictive justice, is absolutely necessary to salvation; and then that men cannot by all their ceremonial and moral services do this; for it is not possible that the blood of bulls and goats should take away sin (Heb. 10:4); as also to lead and direct their views to the sacrifice of Christ, which effectually does it; and without which, to what purpose is the multitude of sacrifices? and vain are all oblations, verses 11, 12.
3. Cease to do evil; which regards either a cessation from ceremonial works, which being done with a wicked mind, were an abomination to the Lord, verses 13, 14, or an abstinence from outward immoralities; such as shedding innocent blood, oppressing the fatherless and widow, verses 15, 17. Now a natural man may be able to abstain from such external enormities of life, without supposing a power in him to do that which is spiritually good; or that the unfrustrable grace of God is unnecessary in conversion.
4. Learn to do well; that is, to do acts of justice, beneficence, liberality, and charity, such as are here mentioned; seek judgment, relieve the oppressed, judge the fatherless, plead for the widow; all which are very commendable, and may be performed by men in an unconverted state; and no way militate either against man’s passiveness, or the necessity of God’s efficacious grace in the work of conversion.
 Ibid. p. 237; ed. 2. 231.