In the book of Isaiah is this prophecy:
"For a child has been born for us, a son given to us; authority rests upon his shoulders; and he is named wonderful Counsellor, Mighty God, Everlasting Father, Prince of Peace."An English version of this antiphon is:Isaiah 9: 6
O king of the nations, and their desire,
the cornerstone making both one:
Come and save the human race,
which you fashioned from clay.
Here is the 'O Rex Gentium' antiphon with the Magnificat (Mary's Song) sung in Latin to a Gregorian chant, but with English subtitles.
Image Credit: John Piper's window Christ in Majesty, Lichfield