21 “The innocent and the upright have cleaved to me, for I have waited for You, O Lord”. The innocent and the upright, not in bodily presence only, as the evil, are mingled with me, but in the agreement of the heart in the same innocence and uprightness cleave to me: for I have not fallen away to imitate the evil; but I have waited for You, expecting the winnowing of Your last harvest.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)