Additional O Antiphons

Medieval breviaries had various additional O-antiphons, all - in my opinion - of inferior form and content to the original seven.

The Parisian Breviary (1735) had nine of these Antiphons, beginning the cycle on the 15th of December, and interpolating two new ones, which I consider to be well-formed and of appropriate structure:

20th December - O Sancte Sanctorum

O Sancte sanctorum, speculum sine macula Dei majestatis, et imago bonitatis illius: veni ut deleatur iniquitas, et adducatur justitia sempiterna.

(O Holy of Holies, the spotless mirror of the power of God, and the image of his goodness: come and blot out iniquity, and bring in everlasting righteousness.)

Sources:

• …speculum sine macula Dei majestatis, et imago bonitatis illius. (Sap 7:26b-c)

• Septuaginta hebdomades abbreviatæ sunt super populum tuum et super urbem sanctam tuam, ut consummetur prævaricatio, et finem accipiat peccatum, et deleatur iniquitas, et adducatur justitia sempiterna, et impleatur visio et prophetia, et ungatur Sanctus sanctorum. (Dan 9:24)
  

23rd December - O Pastor Israël

O Pastor Israël, et dominator in domo David, cujus egressus ab initio, a diebus æternitatis: veni ut pascas populum tuum in fortitudine, et regnes in justitia et judicio. 

(O Shepherd of Israel and ruler of the house of David, whose goings forth have been from of old, from ancient days: come and feed thy people in the strength of the Lord, and reign in judgment and righteousness.)

Some possible sources:

• Qui regis [pascis – 1945] Israël, intende… (Ps 79(80):2(1)a)

• …ex te mihi egredietur qui sit dominator in Israël, et egressus ejus ab initio, a diebus æternitatis. (Mic 5:2c-e)

• ...et relicta est gens perpauca, et princeps in domo David. (Ecclus 48:17)

• ...et erexit cornu salutis nobis in domo David pueri sui... (Lc 1:69)

• Et stabit, et pascet in fortitudine Domini… (Mic 5:4a)

• Et suscitabo super eas pastorem unum qui pascat eas, servum meum David: ipse pascet eas, et ipse erit eis in pastorem. (Ezech 34:23)

• Et scient quia ego Dominus Deus eorum cum eis, et ipsi populus meus domus Israël, ait Dominus Deus. (Ezech 34:30)

• Pasce populum tuum in virga tua, gregem hæreditatis tuæ, habitantes solos, in saltu, in medio Carmeli. Pascentur Basan et Galaad juxta dies antiquos. (Mic 7:14)

• Ecce in justitia regnabit rex, et principes in judicio præerunt. (Is 32:1)