16 “Cast me not forth from Your face”. Turn away Your face from my sins: and “cast me not forth from Your face.” Whose face he fears, upon the face of the Same he calls. “And Your Holy Spirit take not away from me.” For in one confessing there is the Holy Spirit. Even now, to the gift of the Holy Spirit it belongs, that what you have done displeases you. The unclean spirit sins do please; the Holy One they displease. Though then thou still implore pardon, yet you are joined to God on the other part, because the evil thing that you have committed displeases you: for the same thing displeases both you and Him. Now, to assail your fever, you are two, thou and the Physician. For the reason that there cannot be confession of sin and punishment of sin in a man of himself: when one is angry with himself, and is displeasing to himself, then it is not without the gift of the Holy Spirit, nor does he say, Your Holy Spirit give to me, but, “Take not away from me.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)