1 This Psalm, belonging to the number of the Songs of Degrees, teaches us, while we ascend and raise our minds unto the Lord our God in loving charity and piety, not to fix our gaze upon men who are prosperous in this world, with a happiness that is false and unstable, and altogether seductive; where they cherish nothing save pride, and their heart freezes up against God, and is made hard against the shower of His grace, so that it bears not fruit....
2. “They that put their trust in the Lord shall be even as the mount Sion: they shall not be removed for ever”.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)