5 “They will be weakened, and perish from Your face”. Who will be weakened and perish, but the unrighteous and ungodly? “They will be weakened,” while they shall avail nothing; “and they shall perish,” because the ungodly will not be; “from the face” of God, that is, from the knowledge of God, as he perished who said, “But now I live not, but Christ lives in me.” But why will the ungodly “be weakened and perish from your face?” “Because,” he says, “You have made my judgment, and my cause:” that is, the judgment in which I seemed to be judged, You have made mine; and the cause in which men condemned me just and innocent, You have made mine. For such things served Him for our deliverance: as sailors too call the wind theirs, which they take advantage of for prosperous sailing.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)