The psalms were central to the medieval liturgy, and constituted the core of the Divine Office; clergy had to know all the psalms from memory. Psalters contain the texts of the Psalms in Latin translation, either as a section of a larger book for the Divine Office or in a separate volume. In addition to the psalms, a ferial psalter contained the items of the Divine Office that did not change from day to day, often including the invitatories, antiphons canticles, chapters, short responsories (listen), hymns, and litanies

In manuscripts, the psalms were usually divided into groups, each beginning with a major decorated initial. The simplest division into three groups (beginning with psalms 1, 51, 101) is found in early psalters from Ireland and Germany. A five-part division (groups beginning with psalms 1, 41, 72, 89, and 106) is rare. The most common is the eight-part division, with major initials for psalms 1, 26, 38, 52, 68, 80, 97, and 109. These divisions correspond to the groupings of psalms in the Divine Office on successive days of the week in non-monastic churches: psalm 1 was the first psalm of Matins on Sunday, psalm 26 on Monday, psalm 38 on Tuesday, and so on through Saturday. Psalm 109 was the first psalm sung at Sunday vespers. (Monastic and secular uses differed somewhat in their distribution of the psalms over the course of the day and week.)

Western MS 38: A ferial psalter from fifteenth-century Austria
Western MS 38: f. 137:
Psalm 109, the 8th section in the eight-part division of the psalter.
Western MS 38: ff. 193v-194:

Western MS 49, recto:A psalter from 12th century Germany adapted to liturgical use through the addition of antiphons at the bottom of the page. Plimpton MS 040G, recto: A choir psalter from 15th century Italy.

Typographical MS 2: A psalter from 15th century Tuscany
Typographical MS 2f. 1: List of invitatory antiphons for the church year, and a hymn "Primo dierum."
Typographical MS 2f. 15:
Typographical MS 2f. 81:
Typographical MS 2f. 46: Typographical MS 2f. 46:
Canticle "Benedictus."