On the Sunday Dum medium silentium
The Sunday that occurs between Our Lord’s Nativity and Epiphany signifies that time when the Lord was in Egypt. Hence the Communion antiphon Tolle puerum et matrem eius (Matthew 2).
CAP. XVI. – De Dominica, Dum medium silentium.
Dominica, quae inter Nativitatem Domini et Epiphaniae occurrit, significat tempus illud quo Dominus in Aegypto fuit, unde et in communione, Tolle puerum et matrem eius (Matth. II), canitur.
On the Saints and their Octaves
We celebrate the birthdays of saints because through death they were born from this world into eternal life. We keep their octaves because in the octave, i.e. in the Resurrection, their glory will be doubled in Christ.
CAP. XVII. – De sanctis et octavis eorum.
Natalia sanctorum ideo celebrantur, quia de hoc mundo in aeternam vitam per mortem nascebantur. Octavae vero illorum ideo coluntur, quia in octava, id est in resurrectione, gloriae eorum per Christum duplicabuntur.
Formerly the Octave of the Ides of January was a feast for the triple triumph of Augustus Caesar. We celebrate the same day, which we call the Lord’s Epiphany, for three reasons: because a star showed the way to Our Lord and he was revealed to the nations on that day, and after thirty years he was baptized in the Jordan on the same day, and one year later on the same day he was manifested as God at the wedding of Cana through the conversion of water into wine. Thus it is called Epiphany or Theophany, which means appearance or manifestation or showing forth. For it is said that on this day the Lord fed the five thousand from the five loaves. Thus the first nocturn concerns the star’s appearance, the second nocturn the Magi’s visit, and the third Our Lord’s baptism. In the sacraments of the Mass the subject is the conversion of water into wine and the feeding of the people from the loaves.
CAP. XVIII. – De Epiphania.
Octava Idus Ianuarii olim habebatur celebris ob triplicem triumphum Augusti Caesaris. Hanc eamdem diem, quam Epiphaniam Domini vocamus, ob tres causas celebramus, quia Dominus stella duce illa die gentibus est revelatus; et post triginta annos eadem die in Iordane baptizatus, et revoluto anno ipsa die per aquae in vinum conversionem ad nuptias Deus est manifestatus. Ideo Epiphania vel Theophania appellatur, quod apparitio vel manifestatio aut ostentio interpretatur. Traditur enim quod hac die quinque millia hominum de quinque panibus Dominus satiaverit. Itaque in primo nocturno stellae apparitio. In secundo nocturno Magorum visitatio. In tertio Domini baptizatio. In sacramentis missae agitur aquae in vinum conversio, vel populi de panibus saturatio.
On the Magi
The king Zoroaster was the first to discover magic, and from his seed came Balaam who prophesied this about Christ: Orietur stella ex Jacob, et consurget homo de Israel (Numbers 24). The Magi who came to the Lord with gifts were descended from Balaam. Now Magi are a kind of astronomer, experts in the stars. Our Lord wanted to be sought by these men because he wanted a testimony from the wise men of the world on the basis of which the gentile peoples might believe. He wanted to be found by three men because he wanted to be worshipped in the three parts of the world, namely Asia, Africa, and Europe. He wanted to be found through a star because he wanted the people to be converted through Sacred Scripture. He wanted to be found on the twelfth day after his nativity because he wanted to draw the world to himself through the twelve apostles. Now Our Lord wanted to be baptized for three reasons. First, to “fulfill all justice”; second, to endorse the baptism of John; and third to sanctify the waters for us. He wanted to be baptized after thirty years before he began preaching because he wanted to teach the people at the perfect age after he had gained wisdom. He wanted to be baptized by John and no other because from him he wanted a witness among the people because the Jews believed that John was a prophet.
CAP. XIX. – De Magis.
Primus Zoroaster rex magicam invenit, de cuius semine Balaam exstitit, qui de Christo hoc praedixit: Orietur stella ex Iacob, et consurget homo de Israel (Num. XXIV). Ex cuius progenie hi Magi fuerunt, qui ad Dominum cum muneribus venerunt. Magi autem sunt dicti, quasi mathematici, scilicet in stellis periti. Ideo autem Dominus ab his quaeri voluit, quia testimonium a sapientibus mundi habere voluit, quibus et populus gentium credidit. Ideo vero a tribus inveniri voluit, quia a tribus partibus mundi scilicet Asia, Africa, Europa, coli voluit. Ideo hoc per stellam fieri voluit, quia per sacram Scripturam populum converti voluit. Ideo in duodecimo die a nativitate sua hoc fieri voluit, quia per duodecim apostolos mundum attrahere voluit. Propter tres autem causas Dominus baptizari voluit: primo, ut omnem iustitiam impleret: secundo, ut Ioannis baptismum comprobaret: tertio, ut aquas nobis sanctificaret. Idcirco autem post triginta annos baptizari, et tunc praedicare voluit, quia nos adepta scientia in perfecta aetate populum docere voluit. Ideo vero a Ioanne, non ab alio, baptizari voluit, quia ab illo testimonium ad populum habere voluit, quia videlicet populus Iudaeorum illi, ut prophetae, credidit.
On Matins of the Epiphany
In this night, we do not sing the Invitatory, because turn down Herod’s deceitful invitation to the Magi, yet the sixth psalm we sing is Venite exsultemus (Psalm 94), because we celebrate that in the sixth age of the world the gentiles came to the faith. In the third nocturn, we sing the antiphon Fluminis impetus and the psalm Deus noster refugium (Psalm 45), because we remember that, in the third age, the city of God (civitatem Dei), i.e. the Church, was gladdened by the river of baptism. And so in the third nocturn we frequently sing Alleluia, because we announce that in the third age, joy came through the baptism.
CAP. XX. – De Matutinis.
In hac nocte invitatorium non cantamus, quia subdolam Herodis invitationem cum Magis declinamus; in sexto tamen loco psalmum, Venite exsultemus (Psal. XCIV), canimus, quia sexta aetate mundi gentes ad fidem venisse plaudimus. In tertio nocturno antiphonam fluminis impetus (Psal. XLV), et psalmum Deus noster refugium (ibid.), psallimus, quia tertio tempore flumine baptismatis civitatem Dei, scilicet Ecclesiam, laetificasse cognovimus. Ideo in tertio nocturno Alleluia frequentamus, quia in tertio tempore per baptismum laetitiam advenisse annuntiamus.
On the Octave Day of Epiphany
On the Octave Day of Epiphany, we celebrate the baptism of the Church, as in the antiphons Veterem hominem and Te qui in spiritu. Baptism is performed with water, since this element is clearly contrary to fire. Now, the fire of punishment is lit by the kindling of sin, but extinguished by the water of baptism. Hence is it written that in the beginning the Holy Spirit sustained it, for water washes filth away, extinguishes thirst, and restored the image, and so by baptism we are washed of the filth of our sins, drink from the fount of life, and are restored to the image of God.
CAP. XXI. – De octava Epiphaniae.
In octava Epiphaniae baptismus Ecclesiae celebratur, sicut in antiphonis, Veterem hominem, et te qui in spiritu. Ideo autem in aqua baptizatur, quia hoc elementum igni contrarium comprobatur. Fomite vero peccati ignis poenarum accenditur, sed per aquam baptismatis exstinguitur. Ideo hanc Spiritus sanctus in principio fovisse legitur. Aqua enim sordes abluit, sitim exstinguit, imaginem reddit, ita nos baptismate a sordibus peccatorum nostrorum lavamur, a fonte vitae potamur, imagine Dei renovamur.
 This chapter quotes the antiphon Tribus miraculis.
 Fluminis impetus lætificat, alleluia, civitatem Dei, alleluia.
 Veterem hominem renovans Saluator venit ad baptismum ut natura quae corrupta est per aquam recuperaret incorruptibili veste circumamictans nos.
 Te qui in spiritu et igne purificas humana contagia Deum ac redemptorem omnes glorificamus. These and the rest of the day antiphons of the Octave of the Epiphany were of Greek origin, translated into Latin and put into the Roman liturgy at the request of Charlemagne. They were not received into the Roman curial breviary and were therefore not included in the Tridentine breviary.