The Divine Office – or what St Benedict calls the ‘work of God’ – is arguably the most characteristically monastic form of prayer. From the very beginnings of monasticism in Egypt, accounts of the monastic life tell of Psalms being sung to the praise of God, whether by a gathered community of monks, or by solitaries in their cells. In a sense, this is very natural; the Psalter had very much been the prayerbook of the people of Israel, and St Paul advises the Christians in Ephesus to ‘sing psalms and spiritual songs’ at their gatherings.
St Benedict in his Rule takes on the discipline of the Divine Office from the monastic communities he had known and read about, although he does propose his own disposition of the Psalms across the offices on different days of the week. You can find some details about the Office as it is celebrated at Ampleforth here. Benedict is clear that the Office is key in the life of a monk; nothing is to be preferred to it (RB43:3), and an eagerness for the work of God is one of the marks of someone called to the monastic life (RB58:7).
The Office is a public prayer, and this means two things. Firstly, in the Office, the community gathers together visibly, in public, as the local manifestation of the Body of Christ. Secondly, in the Office, the community is very much making its own the prayer of the Church, which is Christ’s prayer to the Father. As with Christ, as we listen to and pray the Psalms and readings, we sometimes praise God as our loving father, while at other times we hear him speaking to us as his beloved children, and at other times again we pray to him for our own needs and the needs of the whole Church and the world.