“The Psalm of All Psalms” is the title the Anglican liturgist J. M. Neale ascribed to this psalm! In the medieval Roman Breviary, Psalm 51 was recited every hour at the conclusion of each monastic service, with the exception of Christmas and the forty-day session of Lent. For some thirteen centuries, it was repeated seven times daily.
medieval liturgical book; a collection of prayers, hymns, psalms, readings, and notations for daily use in Divine Office popular from the eleventh century onward, often developed by a cathedral community.