O Rex Géntium

O Rex géntium, et desiderátus eárum, lapísque anguláris, qui facis útraque unum: veni, et salva hóminem, quem de limo formásti.

O King of the Gentiles, yea, and Desire thereof, O Cornerstone that makest of twain one; come to save man, whom thou hast made of the dust of the earth! 

The 'O Rex géntium'  stanza from 'O Come, O Come Emanuel':

Veni, Veni, Rex Gentium,
Veni, Redemptor omnium,
Ut salves tuos famulos
Peccati sibi conscios. 

Gaude, gaude, Emmanuel
nascetur pro te, Israel. 

O come, Desire of nations, bind
All peoples in one heart and mind;
Bid envy, strife and quarrels cease;
Fill the whole world with heaven’s peace.

Rejoice! Rejoice! Emmanuel
Shall come to thee, O Israel.

The following is from the New Liturgical Movement

The medieval use of Augsburg in Germany contains a particularly interesting enrichment of the liturgy on these days. Each O is accompanied by a special chapter, and a special concluding oration, both of which refer back to it; these form a kind of scriptural and euchological commentary on the much older antiphons. Like many medieval uses, that of Augsburg also added other antiphons to the series, which I will note in another post next week; here are the chapters and prayers which go with the seven oldest antiphons, those found in the Roman Breviary. At Augsburg, the Os began on December 13th, and so I have noted them here.

December 18 (22 in the Roman Breviary)

Capitulum Ecce dies veniunt, dicit Do minus, et suscitabo David germen justum: et regnabit rex, et sapiens erit, et faciet judicium et justitiam in terra.	The Chapter Behold the days come, saith the Lord, and I will raise up to David a just branch: and a king shall reign, and shall be wise, and shall execute judgment and justice upon the earth. (Jeremiah 23, 5)
Aña O Rex gentium, * et desideratus earum, lapisque angularis, qui facis utraque unum: veni, et salva hominem, quem de limo formasti.	Aña O King of the gentiles, * and the Desire thereof, and cornerstone that makest of twain one: come, to save man, whom Thou didst make from the mud of the earth.
Oratio Excita, quaesumus, Domine, potentiam tuam, et veni: ut ab imminentibus peccatorum nostrorum periculis, te mereamur protegente eripi, te liberante salvari: Qui vivis.	The Prayer Stir up Thy strength, o Lord, we beseech Thee, and come; that we may merit to be deli- vered from the imminent dangers of our sins by Thee our protector, and saved by Thee our liberator. Who livest.