“After he had declared his obedience, Jesus revealed to us his glory, saying, ‘I will sing and give praise in my glory: arise, psaltery and harp!’ The psaltery and harp [symbolize] the joy and exultation of his glorious resurrection, and the song and the psalm [symbolize] praise and thanksgiving for this same glory. Christ will sing in his glory. …
Jesus sings in his glory. But to whom does he sing, and what does he sing? He sings to the Father, he sings to the angels, and he will also sing to us.
To the Father he sings eternal eulogies of praise, psalms of triumph and psalms of exaltation, and a new song, the song of songs, which none can sing save Jesus alone: ‘I will extol you, O Lord, for you have sustained me.’ And he sings this: ‘For me you have turned my mourning into joy. You have torn up my sack-cloth and have surrounded me with gladness, so that my glory may sing to you, and I may feel no remorse. O Lord my God, I will give praise to you for ever.’
To the angels he will sing: ‘Rejoice, Jerusalem! Celebrate a feast-day, all you that love her!’ One great angel, falling like lightning from heaven, caused great ruin and drew in his train a third part of the stars. But Christ, in rising from the dead, will fill up the ruins, rebuild the walls of Jerusalem, … Then there will be joy and exultation among the angels, …
Finally, Jesus will sing to us. He will sing a song of joy, a song of delight, saying. ‘Come, you blessed of my father, possess the kingdom prepared for you from the foundation of the world.’ …
In the meantime, [we pray] that the voice of Jesus inviting us to him may grow strong in our hearts. Even now he sings his invitation, saying, ‘If anyone will come after me, let him deny himself, and take up his cross, and follow me.’ The author of life invites us to life: he calls us from labor to rest, singing ceaselessly, ‘Come to me all you who labor and are burdened, and I will refresh you.’ All who hear this voice shall live.”
Baldwin of Forde, Spiritual Tractates, Volume One: Tractate IV “On the Twofold Resurrection which is obtained by perseverance in obedience” (CF 38, p. 107ff.)