Day 54: Chapter 18: In What Order the Psalms Are to Be Said

Vespers are to be sung with four Psalms every day.
These shall begin with Psalm 109 and go on to Psalm 147,
omitting those which are set apart for other Hours;
that is to say that
with the exception of Psalms 117 to 127 and Psalms 133 and 142,
all the rest of these are to be said at Vespers.
And since there are three Psalms too few,
let the longer ones of the above number be divided,
namely Psalms 138, 143 and 144.
But let Psalm 116 because of its brevity be joined to Psalm 115.

The order of the Vesper Psalms being thus settled,
let the rest of the Hour --
lesson, responsory, hymn, verse and canticle --
be carried out as we prescribed above.

At Compline the same Psalms are to be repeated every day,
namely Psalms 4, 90 and 133.

The order of psalmody for the day Hours being thus arranged,
let all the remaining Psalms be equally distributed
among the seven Night Offices
by dividing the longer Psalms among them
and assigning twelve Psalms to each night.

We strongly recommend, however,
that if this distribution of the Psalms is displeasing to anyone,
he should arrange them otherwise,
in whatever way he considers better,
but taking care in any case
that the Psalter with its full number of 150 Psalms
be chanted every week
and begun again every Sunday at the Night Office.
For those monks show themselves too lazy
in the service to which they are vowed,
who chant less than the Psalter with the customary canticles
in the course of a week,
whereas we read that our holy Fathers
strenuously fulfilled that task in a single day.
May we, lukewarm that we are, perform it at least in a whole week!