Psalm 32:5

I acknowledged my sin unto thee
The sin of Adam, in which he was concerned; original sin, the corruption of his nature, the sin that dwelt in him, his private and secret sins, which none knew but God and himself; even all his sins, which were many, with all their aggravated circumstances; wherefore he uses various words to express them by, in this and the following clauses; as "sin", "iniquity", and "transgressions"; the same that are used in the doctrine of pardon in the preceding verses; his confession being of the same extent with pardon, and all these he calls his own; as nothing is more a man's own than his sins are; and these the psalmist acknowledged to the Lord; or "made", or "will make known" ^F16 to him: not that any sin is unknown to God, even the most secret ones; but they may be said to be made known to God, when a sinner makes a sincere and hearty acknowledgment of them before him, and expresses his own sense of them; how that they are with him, and ever before him, what knowledge rather he has of them, how much he is affected with them, and concerned for the commission of them; and such an acknowledgment the Lord expects and requires of his people, ( Jeremiah 3:12 Jeremiah 3:13 ) ;

and mine iniquity have I not hid;
by retaining it as a sweet morsel under his tongue; for he not only acknowledged it, but forsook it; or by not confessing it, as Achan; for not confessing sin is the of hiding it; or by denying it, as Gehazi, Ananias and Sapphira; or by palliating and extenuating it; or by casting the blame on others, as did Adam and his wife; see ( Job 31:33 ) ; or by covering it with a guise of sanctify and religion;

I said, I will confess my transgressions unto the Lord;
not unto men, though in some cases confession of sin is to be made to men; a confession of it in general is to be made to the churches, and administrators of ordinances, in order to admission into a church state, and to the ordinances of Christ, ( Matthew 3:6 ) ( Acts 2:37 Acts 2:41 ) ; and in case of private offences, faults are to be confessed one to another, and forgiveness granted; and in case of public offences, a confession should be made to a church publicly; partly for the satisfaction of the church, and partly for the glory of divine grace; but confession is not to be made to a priest, or to a person in a ministerial character, in order for absolution; but to the Lord only, against whom sin is committed, and who only can pardon it: and this the psalmist saith in his heart he would do, and did do it; he not only confessed facts, but the fault of them, with their evil circumstances, and that he justly deserved punishment for them; and this he did from his heart, with abhorrence of the sins committed by him, and in faith, with a view to the pardoning mercy of God in Christ;

and thou forgavest the iniquity of my sin.
That is, either the guilt of his sin, which he took away from him; or the punishment of it, which he delivered him from: moreover, this phrase may denote the exceeding sinfulness of sin, and so may both express the sense which the psalmist had of it, and exalt the grace of God in the forgiveness of it; by which must be meant a fresh manifestation and application of pardon to his soul: now, when confession of sin, and remission of it, are thus put together, the sense is not that confession of sin is the cause of pardon; it is not the moving cause of it, that is the grace and mercy of God; nor the procuring and meritorious cause of it, that is the blood of Christ: it is not for the sake of a sinner's confession of sin, but for Christ's sake, that sin is forgiven; but this is the way in which it is enjoyed; and such as truly repent of sin, and sincerely confess it, are the persons to whom the Lord manifests his forgiving love; such may expect it, ( Proverbs 28:13 ) ( 1 John 1:9 ) .

Selah; on this word, (See Gill on Psalms 3:2).