9 “So I will play music to Your name, that I may render my vows from day unto day”. If you play music to the name of God, play not for a time. Will you for ever play? Will you for everlasting play? Render to Him your vows from day unto day. What is, render to Him your vows from day unto day? From this day unto that day. Continue to render vows in this day, until you come to that day: that is, “He that shall have continued even unto the end, the same shall be saved.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)