7 “In God will we boast all the day long”. Observe how he intermingles words expressive of a future time, that you may perceive that what was spoken of before as in past time was foretold of future times. “In God will we boast all day long; and in Your name will we confess for ever.” What is, “We shall boast”? What, “We shall confess”? That You have “saved us from our enemies;” that You are to give us an everlasting kingdom: that in us are to be fulfilled the words, “Blessed are they that dwell in Your house: they will be always praising You.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)