How many psalms are to be said in the night-hours.
In winter, having first said the verse, “O God incline unto mine aid, O Lord make haste to help me,”156 the words, “O Lord open my lips, and my mouth shall declare Thy praise,”157 are next to be repeated three times After this the third Psalm is said, with a “Glory be to the Father,” at the end. Then the ninety-fourth Psalm is to be recited or sung with an antiphon. Let hymn follow next, and then six psalms with antiphons. These being said, and a versicle added, let the Abbot give a blessing, and then, all being seated, let three lessons be read by the Brethren in turns, from the book lying on the lectern. After every lesson, let a responsory be sung. Let two of them be without a “Gloria,” but after the third let it be added by the Cantor, and as soon as he has begun it, let all rise from their seats our of honour and reverence to the Holy Trinity.
Let the divinely inspired books, both of the Old and New Testament, be read at Matins, together with the expositions made upon them by the most famous, orthodox, and Catholic Fathers. After these three lessons and their responsories, let six other psalms follow, to be sung with an Alleluia. Then let a lesson from the Apostle be said by heart, and after that a verse and the supplication of the Litanies, that is, “Kyrie eleison.” And thus let the Matins or Night-watches be brought to an end.