8 “O Lord, in Your will You have afforded strength unto my beauty”. But that this my abundance, O Lord, is not of myself, but that in Your will You have afforded strength unto my beauty, I have learned from this, “You turned away Your Face from me, and I became troubled;” for You have sometimes turned away Your Face from the sinner, and I became troubled, when the illumination of Your knowledge withdrew from me.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)