ChapterII-III. Office of Readings
55. The office of readings seeks to provide God's people, and in particular those consecrated to God in a special way, with a wider selection of passages from sacred Scripture for meditation, together with the finest excerpts from spiritual writers. Even though the cycle of scriptural readings at daily Mass is now richer, the treasures of revelation and tradition to be found in the office of readings will also contribute greatly to the spiritual life. Bishops and priests in particular should prize these treasures, so that they may hand on to others the word of God they have themselves received and make their teaching "the true nourishment for the people of God." 
56. But prayer should accompany "the reading of sacred Scripture so that there may be a conversation between God and his people: 'we talk with God when we pray, we listen to him when we read God's words."  For this reason the office of readings consists also of psalms, a hymn, a prayer, and other texts, giving it the character of true prayer.
57. The Constitution on the Liturgy directs that the office of readings, "though it should retain its character as a night office of praise when celebrated in choir, shall be adapted so that it may be recited at any hour of the day; it shall be made up of fewer psalms and longer readings." 
58. Those who are obliged by their own particular law and others who commendably wish to retain the character of this office as a night office of praise (either by saying it at night or very early in the morning and before morning prayer), during Ordinary Time choose the hymn from the selection given for this purpose. Moreover, for Sundays, solemnities, and certain feasts what is said in nos. 70-73 about vigils must be kept in mind.
59. Without prejudice to the regulations just given, the office of readings may be recited at any hour of the day, even during the night hours of the previous day, after evening prayer has been said.
60. If the office of readings is said before morning prayer, the invitatory precedes it, as noted (nos. 34-36). Otherwise it begins with the verse, God, come to my assistance with the Glory to the Father, As it was in the beginning, and the Alleluia (omitted in Lent).
61. Then the hymn is sung. In Ordinary Time this is taken either from the night selections, as already indicated (nos. 34-36), or from the morning selections, depending on what the true time of day requires.
62. The psalmody follows and consists of three psalms (or parts in the case of longer psalms). During the Easter triduum, on days within the octaves of Easter and Christmas, on solemnities and feasts, the psalms are proper, with their proper antiphons.
On Sundays and weekdays, however, the psalms and their antiphons are taken from the current week and day of the psalter. On memorials of the saints they are similarly taken from the current week and day of the psalter, unless there are proper psalms or antiphons (see nos. 218ff.).
63. Between the psalmody and the readings there is, as a rule, a verse, marking a transition in the prayer from psalmody to listening.
64. There are two readings: the first is from the Scriptures, the second is from the writings of the Fathers or church writers, or else is a reading connected with the saints.
65. After each reading there is a responsory (see nos. 169-172).
66. The scriptural reading is normally to be taken from the Proper of Seasons, in accordance with the rules to be given later (nos. 140-155). On solemnities and feasts, however, it is taken from the proper or the common.
67. On solemnities and feasts of saints a proper second reading is used; if there is none, the second reading is taken from the respective Common of Saints. On memorials of saints when the celebration is not impeded, the reading in connection with the saint replaces the current second reading (see nos. 166 and 235).
68. On Sundays outside Lent, on days within the octaves of Easter and Christmas, and on solemnities and feasts the Te Deum is said after the second reading with its responsory but is omitted on memorials and weekdays. The last part of this hymn, that is, from the verse, Save your people, Lord to the end, may be omitted.
69. The office of readings normally concludes with the prayer proper to the day and, at least in recitation in common, with the acclamation, Let us praise the Lord. R. And give him thanks.