Verily, I have cleansed my heart in vain
Which supposes that his heart had been unclean, as every man's is, and which appears by what is in it, and by what comes out of it; that it was now cleansed, not in an absolute and legal sense, as if it was wholly free from sin, for this no man can say; but in an evangelical sense, being purified by faith in the blood of Christ; that he had himself some concern in the cleansing of his heart, which seems to be contrary to ( Proverbs 20:9 ) and besides, this is the Lord's own work, ( Psalms 51:10 ) ( Ezekiel 36:25 ) wherefore this may be considered as a wrong and rash expression of his; for as he was wrong in one part of it, its being cleansed in vain, so he might be in the other, in ascribing it to himself; though it may be allowed, consistent with what is before observed, that a believer has a concern in the cleansing of his heart; for, being convinced of the impurity of it, he owns and laments it before the Lord; and, seeing the fountain of the Redeemer's blood opened, he applies to it, and to him for cleansing; and expresses a love unto, a great and studious concern for purity of heart as well as life; and, under the influence of divine grace, is enabled to keep a watch over it, whereby, through the same grace, it is preserved from much pollution; and by fresh application to the blood of Christ, is cleansed from what it daily contracts:
and washed my hands in innocency:
that is, "in vain", as before; which denotes the performance of good works, a course of holy life and conversation, which when right springs from purity of heart; (See Gill on Psalms 26:6), now the psalmist under temptation concluded that all his religion and devotion were in vain, all his hearing, and reading, and attending on ordinances, all his concern for purity of heart and life; since those who showed no regard to these things prospered in the world, and increased in riches, abounded in ease and plenty, and seemed to be rather the favourites of heaven than religious men; and this temptation was strengthened by the following observation.