O admirable exchange: the creator of the humankind, taking on a living body deemed worthy to be born of a virgin, and, coming forth without seed as a man, gave us his deity.

Full text: I-Mfd 3, ff. 168v-169r
Translation: Eva Ferro
O admirabile commercium, creator generis humani, animatum corpus sumens de virgine nasci dignatus est et procedens homo sine semine largitus est nobis suam deitatem.
O admirable exchange: the creator of the humankind, taking on a living body deemed worthy to be born of a virgin, and, coming forth without seed as a man, gave us his deity.
Antiphon at Lauds for the Octave of Christmas (also used in the Little Office of the BVM during Christmastide), Cantus ID 003985
Psallenda for the feast of Annunciation, see PM 6, 45
LU lists the antiphons whose texts are used in T085-T088 to be sung in consecutive order at 2nd vespers on the feast of Circumcision.