With voices in harmony and hearts in concord we have begged the Lord for our own hearts by saying, Create a clean heart in me, O God and renew an upright spirit in my bowels (Ps 50:12) …..*see Ps 51:10 new nos. and translation.
It’s a psalm of someone repenting, someone wishing to retrieve the hope he had lost, lying where he had fallen, begging the Lord to give him a had to raise him up again; like someone quite capable of injuring himself but not of healing himself. After all, we can stab and wound our own flesh whenever we want, but to heal it we look for a doctor; well, in the same way the soul is perfectly able to sin all by itself, but to heal the hurt it has caused by sinning, it implores the helping hand of God.
That’s why he says in another psalm, I myself have said, Lord. Have mercy on me, heal my soul since I have sinned against you (Ps 40:4). see Ps 41:4 new nos. & translation The reason he says I myself have said it, Lord, is to thrust before our eyes the fact that the will and decision to sin arises from the soul and that we are fully capable of destroying ourselves, while it takes God to seek that which was lost and to save that which has wounded itself. For the Son of Man has come to seek and save that which was lost (Lk 19:10). It is Him that we pour out our prayers and say Create a clean heart in me, O God, and renew an upright spirit in my bowels (Ps 50:12). *see Ps 51:10 new nos. and translation. Let the soul that has sinned say this, or it may perish twice over through despair, having lost itself once already by its delinquency.
Saint Augustine of Hippo +430