John Gill's Exposition of the Whole Bible
Proverbs 28:13
He that covereth his sins shall not prosper,.... God may cover a man's sins, and it is an instance of his grace, and it is the glory of it to do it, but a man may not cover his own: it is right in one good man to cover the sins of another, reproving him secretly, and freely forgiving him; but it is wrong in a man to cover his own: not that any man is bound to accuse himself before a court of judicature, or ought to expose his sins to the public, which would be to the hurt of his credit, and to the scandal of religion; but whenever he is charged with sin, and reproved for it by his fellow Christian, be should not cover it, that is, he should own it; for not to own and acknowledge it is to cover it; he should not deny it, which is to cover it with a lie, and is adding sin to sin; nor should he justify it, as if he had done a right thing; nor extenuate or excuse it, or impute it to others that drew him into it, as Adam, which is called a covering transgression, as Adam, Job 31:33; for such a man "shall not prosper"; in soul or body, in things temporal or spiritual; he shall not have peace of mind and conscience; but, sooner or later, shall feel the stings it; he shall not succeed even in those things he has in view by covering his sins; he shall not be able to cover them long, for there is nothing covered but what shall be revealed; if not in this life, which yet often is, however at the day of judgment, when every secret thing shall be made manifest; nor shall he escape the shame and punishment he thought to avoid by covering it, as may be observed in the case of Achan, Joshua 7:11; in short, he shall have no mercy shown him by God or man, as appears by the antithesis in the next clause;
but whoso confesseth and forsaketh [them] shall have mercy; who confesses them to men privately and publicly, according to the nature of the offences, from whom they find mercy; but not to a priest, in order for absolution, which no man can give; sin is only in this sense to be confessed to God, against it is committed, and who only can pardon it; and though it is known unto him, yet he requires an acknowledgment of it, which should be done from the heart, with an abhorrence of the sin, and in the faith of Christ, as a sacrifice for it; and it is not enough to confess, there must be a forsaking likewise, a parting with sin, a denying of sinful self, a leaving the former course of sin, and a quitting the company of wicked men before used to, and an abstaining from all appearance of evil; as is and will be the case, where there is a true sight and sense of sin, and the grace of God takes place: and such find "mercy", pardoning grace and mercy, or pardon in a way of mercy, and not merit; for though the sinner confesses and forsakes it, it is not that which merits pardon and mercy in God, who is rich in it, delights in showing it, and from whom it may be hoped for and expected by all such persons; see
Psalms 32:5. So the Targum and Syriac version, God will have mercy on him.