1 This Psalm, even as we ourselves have been singing with gladness together with you, we would beg you in like manner to consider with attention together with us. For it is sung of the sacred Marriage-feast; of the Bridegroom and the Bride; of the King and His people; of the Saviour and those who are to be saved....His sons are we, in that we are the “children of the Bridegroom;” and it is to us that this Psalm is addressed, whose title has the words, “For the sons of Korah, for the things that shall be changed.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)