Heading to a new subsection of Chapter III, we get to the topic of Reading of Sacred Scripture in General
140. The reading of sacred Scripture, which, following an ancient tradition, takes place publicly in the liturgy, is to have special importance for all Christians, not only in the celebration of the eucharist but also in the divine office. The reason is that this reading is not the result of individual choice or devotion but is the planned decision of the Church itself, in order that in the course of the year the Bride of Christ may unfold the mystery of Christ “from his incarnation and birth until his ascension, the day of Pentecost, and the expectation of blessed hope and of the Lord’s return.” [SC 102.] In addition, the reading of sacred Scripture in the liturgical celebration is always accompanied by prayer in order that the reading may have greater effect and that, in turn, prayer – especially the praying of the psalms – may gain fuller understanding and become more fervent and devout because of the reading.
The principle of a Catholic Lectionary is encapsulated here: readings at liturgy are not a choice by the leader or community. They are not based on devotion. The Scripture reading is at once an infusion into the prayer that accompanies it, and it is placed into the context of public prayer so as to be highlighted spiritually for those who hear. And hopefully those hearing will respond.
141. In the liturgy of the hours there is a longer reading of sacred Scripture and a shorter reading.
142. The longer reading, optional at morning prayer and evening prayer, is described in no. 46.