The Three Nativities of the Three Christmas Masses

Lost in Translation #66

In the Summa Theologiae, St. Thomas Aquinas explains the tradition in the Roman Rite of having three different Masses on Christmas Day:

On Christmas Day… several Masses are said on account of Christ’s threefold Nativity. Of these the first is His eternal birth, which is hidden in our regard, and therefore, one Mass is sung in the night, in the Introit of which we say, “The Lord said unto Me: Thou art My Son, this day have I begotten Thee.” The second is His Nativity in time, and the spiritual birth, whereby Christ rises “as the day-star in our hearts” (2 Pet. 1, 19), and on this account the Mass is sung at dawn, and in the Introit we say, “The light will shine on us today.” The third is Christ’s temporal and bodily birth, according as He went forth from the virginal womb, becoming visible to us through being clothed with flesh: and on that account the third Mass is sung in broad daylight, in the Introit of which we say, “A child is born to us.” Nevertheless, on the other hand, it can be said that His eternal generation, of itself, is in the full light, and on this account in the Gospel of the third Mass mention is made of His eternal birth. But regarding His birth in the body, He was literally born during the night, as a sign that He came to the darknesses of our infirmity; hence also in the Midnight Mass we say the Gospel of Christ’s Nativity in the flesh. (III.83.2)

Deus, qui hanc sacratíssimam noctem veri lúminis fecisti illustratióne claréscere: da, quáesumus: ut, cujus lucis mysteria in terra cognóvimus, ejus quoque gaudiis in caelo perfruámur. Qui tecum vivit.

O God, who hast made this most sacred night to shine with the brightness of the True Light, grant, we beseech: that we who have known the mysteries of His light on earth may also relish His joys in Heaven. Who with Thee. 

Da nobis, quǽsumus, omnípotens Deus: ut, qui nova incarnáti Verbi tui luce perfúndimur; hoc in nostro respléndeat ópere, quod per fidem fulget in mente. Per eúmdem Dóminum.

Grant, we beseech Thee, almighty God: that we, upon whom is poured forth the new light of Thy Incarnate Word, may show forth in our work that which shineth by faith in our minds. Through the same our Lord.

Concéde, quáesumus, omnípotens Deus: ut nos Unigéniti tui nova per carnem natívitas líberet; quos sub peccáti jugo vetusta sérvitus tenet. Per eundem Dóminum.

Grant, we beseech Thee, almighty God, that the new birth in the flesh of Thine only-begotten Son may set us free, whom the old bondage doth hold under the yoke of sin. Through the same our Lord.