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

The antiphon of the Introït is taken from Psalm 85: "Have mercy on me, O Lord, for I have cried to Thee all the day; for Thou, O Lord, art sweet and mild and plenteous in mercy to all that call upon Thee."

The Gradual is taken from Psalm 101, and is the same as the one sung for the Third Sunday after the Epiphany: "The Gentiles shall fear Thy name, O Lord, and all the kings of the earth Thy glory. For the Lord hath built up Sion, and He shall be seen in His majesty."

The versicle of the Alleluia belongs to Psalm 97: "Sing ye to the Lord a new canticle, because the Lord hath done wonderful things."

The versicle of the Offertory, the same as for the Friday of the second week of Lent, belongs to Psalm 39: "Look down, O Lord, to help me; let them be confounded and ashamed that seek after my soul to take it away; look down, O Lord, to help me."

The verse sung during the Communion is taken from Psalm 70; it is the same as for the Thursday after the Fourth Sunday of Lent: "O Lord, I will be mindful of Thy justice alone: Thou hast taught me, O God, from my youth, and unto old age and grey hairs, O God, forsake me not."