23 “And my sorrow is continually before me.” What “sorrow” is that? Perhaps, a sorrow for my scourge. And, in good truth, my brethren, in good truth, let me say unto you, men do mourn for their scourges, not for the causes on account of which they are scourged. Not such was the person here. Listen, my brethren: If any person suffers any loss, he is more ready to say, “I did not deserve to suffer it,” than to consider why he suffered it, mourning the loss of money, not mourning over that of righteousness.
If you have sinned, mourn for the loss of your inward treasure. You have nothing in your house, but perhaps you are still more empty in heart; but if your heart is full of its Good, even your God, why do you not say, “The Lord gave, the Lord has taken away; as it pleased the Lord was it done. Blessed be the Name of the Lord.” Whence then was it that He was grieving? Was it for the “scourging” wherewith He was scourged? God forbid. “And my sorrow” (says He) “is continually before me.”
And as if we were to say, “What sorrow? Whence comes that sorrow?” he says: “For I declare mine iniquity; and I will have a care for my sin”. See here the reason for the sorrow! It is not a sorrow occasioned by the scourge; not one for the remedy, not for the wound. For the scourge is a remedy against sins. Hear, brethren; We are Christians, and yet if any one's son dies, he mourns for him but does not mourn for him if he sins. It is then, when he sees him sinning, that he ought to make mourning for him, to lament over him.
It is then he should restrain him, and give him a rule to live by; should impose a discipline upon him: or if he has done so, and the other has not taken heed, then was the time when he ought to have been mourned over; then he was more fatally dead while living in luxury, than when, by death, he brought his luxury to its close: at that time, when he was doing such things in your house, he was not only “dead, but he stank also.” These things were worthy to be lamented, the others were such as might well be endured; those, I say, were tolerable, these worthy to be mourned over.
They were to be mourned over in the same way that you have heard this person mourn over them: “For I declare mine iniquity. I will have a care for my sin.” Be not free from anxiety when you have confessed your sin, as if always able to confess your sin, and to commit it again. Do thou “declare your iniquity in such a manner, as to have a care for your sin.” What is meant by “having a care of your sin”? To have a care of your wound. If you were to say, “I will have a care of my wound,” what would be meant by it, but I will do my endeavour to have it healed.
For this is “to have a care for one's sin,” to be ever struggling, ever endeavouring, ever exerting one's self, earnestly and zealously, to heal one's wound. Behold! You are from day to day mourning over your sins; but perhaps your tears indeed flow, but your hands are unemployed. Do alms, redeem your sins, let the poor rejoice of your bounty, that you also may rejoice of the Grace of God. He is in want; so are you in want also: he is in want at your hands; so are you also in want at God's hand.
Do you despise one who needs your aid; and shall God not despise you when you need His? Do thou therefore supply the needs of him who is in want of your aid; that God may supply your needs within. This is the meaning of, “I will have a care for my sin.” I will do all that ought to be done, to blot out and to heal my sin. “And I will have a care for my sin.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)