Summary of comments of this office by Dom Schuster, in his work L'année liturgique.

The Introït is that of the third Mass of Christmas.

The psalm of the Gradual, as well as the reading from St. Paul, are the same as those of the Midnight Mass of Christmas.

The Alleluia, on the contrary, harmonizes with the reading from the third Mass of Christmas, and it is probably out of place: "God, who in divers manners spoke in times past to the fathers by the prophets, last of all in these days hath spoken to us by His Son."

The antiphon of the Offertory is the same as in the third Mass of Christmas, as is the antiphon of the Communion.