It's right there in the Bible. Which I noticed this morning because the breviary points this out in the subheading beneath the Old Testament canticle from Exodus. (Which begins, I will sing to the Lord, for he is gloriously triumphant; horse and chariot he has cast into the sea...)
This is the song of Moses, Miriam, and the Israelites who had just successfully crossed the Red Sea and witnessed the destruction of the pursuing Egyptians. The breviary usually helps us, with a brief line, to apply the psalms and canticles to some truth of the New Covenant. So today, just ahead of the canticle, we find this line from the book of Reveleation: Those who had conquered the beast were singing the song of Moses, God's servant (see Revelation 15:2-3)
I looked this up, and found not only the verse, but also this helpful footnote (this is the Ignatius Catholic Study Bible): "John sees and hears the martyrs of heaven standing beside the glassy sea and singing praises to God. They sing an adapatation of the Song of Moses from Ex. 15: 1-18...here the saints celebrate a new Exodus from the sin and slavery of the world....In the end, the Lord will lead [the Church] out of this world into his own inheritance, which was not conferred by Moses, the servant of God, but by Jesus the Son of God..."
Although the title of this post exaggerated a bit to get your attention, this snippet of Revelation does show us:
- The saints in heaven pray the songs of Sacred Scripture
- They, like us as we pray the Liturgy of the Hours, apply the words of scripture to their own situation, to the Church, and to Jesus in the oneness of the Mystical Body.
And when you are praying the hours today, reflect that when you do so, you are joining with the whole Church, not just world wide, but eternity wide.