CHAPTER XVIII. In What Order the Psalms Are to Be Said
24 Feb. ( if it be leap-year; if not it is added to the preceding day). 25 June. 25 Oct.
The order of psalmody for the Day-Hours being now arranged, let all the remaining 25 Psalms be equally distributed among the seven Night Offices, dividing the longer Psalms among them, and assigning twelve to each night. Above all, we recommend that if this arrangement of the Psalms be displeasing to anyone, he should, if he think fit, order it otherwise; taking care in any case that the whole Psalter of a hundred and fifty Psalms be recited every week, and always begun afresh at the Night Office on Sunday. For those monks would shew themselves very slothful in the divine service who said in the course of a week less than the entire Psalter, with the usual canticles; since we read that our holy fathers resolutely performed in a single day what I pray we tepid monks may achieve in a whole week.

One Non-Negotiable
With this section of Chapter XVIII, our father Saint Benedict completes his distribution of the 150 psalms over the course of the week. This being done, he shows his humility and reasonableness by allowing for a different arrangement of the psalms, but under one condition: that the whole Psalter of a hundred and fifty Psalms be recited every week, and always begun afresh at the Night Office on Sunday. So clear is Saint Benedict on this particular point, that one cannot depart from the principle of the recitation of the whole Psalter of a hundred and fifty psalms over the week, without stepping outside the margins of the Holy Rule. The distribution of the Psalter over one week is one of the very few non-negotiables laid down by Saint Benedict.

We Tepid Monks
Why is Saint Benedict so insistent on this principle? He explains: “Those monks would shew themselves very slothful in the divine service who said in the course of a week less than the entire Psalter, with the usual canticles; since we read that our holy fathers resolutely performed in a single day what I pray we tepid monks may achieve in a whole week.” It is clear, then, that Benedictines are bound to pray the Psalter in its entirety weekly.

Benefits
Wonderful benefits accrue from the weekly repetition of the Psalter: the psalms become familiar, sometimes to the point of being memorised; the taste of them lingers for a long time on the palate of the soul; they become the ground of an authentic Christian contemplation, for by them, the prayer of Christ passes into us, and we pass into His prayer to the Father.