O King of the Nations — December 22

O Rex gentium, et desideratus earum, lapisque angularis, qui facis utraque unum: veni et salva hominem, quem de limo formasti.

http://www.youtube.com/watch?v=Xd3QaB4fimM&feature=channel

O King of all the nations, the only joy of every human heart; O Keystone of the mighty arch of man: come and save the creature you fashioned from the dust. — translation in current Catholic Liturgy of the Hours

O come, desire of nations, bind / In one the hearts of all mankind; / Bid thou our sad divisions cease, / And be thyself our king of peace. — Verse translation in "O Come, O Come, Emmanuel"

O Rex Gentium — O King of the nations (or gentiles) — Psalm 2:6-8, Jeremiah 10:7, Daniel 7:14, Revelation 15:3

desideratus earum — their desired — Haggai 2:8 (in the King James translation), Malachi 3:1

lapisque angularis — and cornerstone — Ephesians 2:20, Isaiah 28:16

qui facis utraque unum — who makes both [into] one — Ephesians 2:14