The Psalter is the most well-known book in the worship life of our Church. It is used daily in every Service (Vespers, Matins, Hours, etc.), and, in the form of individual Psalms or verses, in the Divine Liturgy and other Sacraments. The entire hymnology of our Church is based on it. The prophet David composed it moved by the Holy Spirit, and for this reason, its verses contain deep meanings. The Psalter is a "public treasury of teaching," a "common clinic, which contains the remedy for every passion," according to the great Basil.