14 But consider how the gates of righteousness are entered into. “These are the gates of the Lord” he says, “the righteous shall enter into them”. At least let no wicked man enter there, that Jerusalem which receives not one uncircumcised, where it is said, “Without are dogs.” Be it enough, that in my long pilgrimage “I have had my habitation among the tents of Kedar:” I endured even unto the end the intercourse of the wicked, but “these are the gates of the Lord: the righteous shall enter into them.”
15. “I will confess unto You, O Lord, for You have heard me, and have become my salvation”. How often is that confession proved to be one of praise, that does not point out wounds to the physician, but gives thanks for the health it has received. But the Physician Himself is the Salvation.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)