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

The inspiration for the last part of the Introït comes from the Book of Tobias (12:6). It is a hymn of praise to God One-and-Three. The versicle is from Psalm 8, where divine beauty and goodness, spread with such magnificence throughout creation, are magnified.

The Gradual respond is taken from Daniel (3:55-56): "Blessed art Thou, O Lord, that beholdest the depths and sittest upon the Cherubim. Blessed art Thou, O Lord, in the firmament of heaven, and worthy of praise for ever."

The versicle of the Alleluia is that of the preceding night, after the reading from Daniel. God is called "the God of our fathers" to show that their souls live near Him-He is not the God of the dead but of the living-and that He is the author of the magnificent promises made to the patriarchs and prophets.

The antiphon for the Offertory, as for the Introit, is inspired by the Book of Tobias: it is a benediction of the august Trinity.

The antiphon for the Communion also comes from the passage of Tobias cited above. We publish the glory of the Holy Trinity before all men, while in our understanding, our memory, our will, our acts, we keep unsullied the divine image.