Bridges on Proverbs 20:9
Charles Bridges on Proverbs 20:9

9.  Who can say, I have made my heart clean, I am pure from my sin?
Behold the Great King sitteth on the throne of judgment, and challenging every child of Adam — “Gird up now thy loins like a man; for I will demand of thee; and answer thou me.” (Job 38:3.) The question is confounding. The answer humbles us in the dust — Who can say — truly say — I have made my heart clean? A sinner in his self-delusion may conceive himself to be a saint. But that a saint should ever believe that he made himself so — , is impossible. Who can say — I am pure from my sin? What! no vain thoughts, no sinful imaginations lodging within! No ignorance, pride, wandering, coldness, worldliness, unbelief indulged! The more we search the heart, the more will its impurity open upon us. “Turn thou yet again, and thou shalt see greater abominations” (Ezekiel 8:13), evils hitherto unsuspected. Vain boasters there are, who proclaim their good hearts. But the boast proves, not their goodness, but their blindness; that man is so depraved that he cannot understand his own depravity.† What say they, who have entered into the presence of the King, whose holiness scattereth away all evil? “Behold! I am vile!” said one. “Now mine eye seeth thee. Wherefore I abhor myself.” “Woe is me” — said another — “for I am a man of unclean lips, for mine eyes have seen the King, the LORD of hosts.”† Take again one — counted as the foremost of the saints of God; a very flame of love for Christ and his Church; “in labors more abundant than all;” in tenderness as a mother for her new-born child; in walk “holy, just, and unblameable” — does he speak of his purity from sin? Verily in his highest state of Christian attainment he feels himself to be the chief of sinners — a wondrous “pattern of Divine long-suffering.” (1 Timothy 1:15, 16.) Such was the mighty power of depravity, mingled with such shining grace, that but for a miracle of instant Almighty help, he might have been thrown from “the third heavens into the snare of the devil.”† To descend to the level near to our own day. ‘Once I thought’ — said a holy man of God — ‘some humiliating expressions of the saints of God too low for me — proud, blind wretch as I was! Now I can say with Edwards — ‘Infinite upon infinite only reaches to my sinfulness.’ ’† And indeed there is not a conscious child of God that does not drink into this self-abased spirit. But for the clear manifestation of gospel grace, should we not have cause to tremble, lest our sins — after such multiplied engagements on our part, and such tender long-suffering on God’s part — should remain in all their hundredfold aggravations uncanceled in the great account, and consign us in just demerit “to everlasting punishment”? The clean heart therefore is not the heart pure from sin, but the heart cleansed and renewed by grace. And truly, if none can say — I have made my heart clean, myriads can witness to the blood of him who is the Son of God, cleansing it from guilt (1 John 1:7), and to the mightiness of the Creator to renew it unto holiness.
But are there not many, who in the house of God will confess themselves miserable sinners, and at the holy table will acknowledge ‘the burden of their sin to be intolerable,’ who yet will go back to the world, and boast or comfort themselves in the confidence of their goodness? confessing indeed that they are sinners, but stoutly warding off every charge of sin? Ah! such are not “the heavy-laden,” to whom Christ hath promised “rest” (Matthew 11:28); not “the lost, whom the Son of Man is come to seek and to save.” (Luke 19:10.) They will lie beside the cleansing fountain, but never care to “wash and be clean.” But observe in this proverb the fundamentals of the gospel — man’s total corruption; his inability to make his heart clean; and his grievous tendency to self-deception. Hence his need. Hence, when that need is felt, the value of the cleansing remedy. “If I wash thee not, thou hast no part in me.” If this be so, then, Lord, “not my feet only, but my hands and my head.” (John 13:8, 9.) “Wash me throughly from my transgressions, that I may be whiter than snow. Create in me a clean heart, O God, and renew a right spirit within me.” (Psalm 51:2, 7, 10.)