Durandus on the Divine Office of the Circumcision

The octave of the Nativity expresses a two-fold matter: one part is the Circumcision of the Lord, which is narrated in the Gospel (Luke 2, 21), the other is the coming of man to God. For there is a two-fold coming, namely, of Christ to men, which is celebrated in the Nativity, and of men to Christ, which is celebrated on its octave, as noted by the antiphons of Lauds, e.g. “O wondrous commerce!”

The Circumcision of the Lord, and the beginning of the Mass for the feast, from the Salzburg Missal.

For commerce is when something is received and something given., and the Lord received our humanity, that He might give us His divinity, as is noted in the words that follow, “taking on a living body from the Virgin.” This tells us what the Lord received, and the words “bestowed us His divinity”, tell us what He gave. The second and fourth antiphons end with the words, “We praise Thee, o our God!”, as if to say, “We shall come to Thee by praising Thee.” The third ends with, “Mother of God, intercede for us,” as if to say, “Intercede, that thy Son may receive us.” In the fifth are said the words of the Baptist, “Behold the Lamb of God”, as if to say, “We must come to Him”, whence Andrew and John’s other disciple on hearing this followed the Lord. (John 1, 35-37) But in the antiphon at the Benedictus is said, “Natures are renewed,” for our nature was made old by departing from God, and renewed by returning to Him. (Rat. Div. Off. VI, 15, 14-15)

Aña A wonderful mystery is declared today: natures are renewed, God hath become man: He has remained what He was, and taken on what He was not, suffering neither mixture nor division.

Aña Mirábile mysterium declarátur hodie: innovantur natúrae, Deus homo factus est: id quod fuit permansit, et quod non erat assumpsit, non commixtiónem passus, neque divisiónem.

A polyphonic setting of this text by the Slovene composer Jacob Handl (1550-91), also known as Jacobus Gallus.