Kathisma

A Kathisma (Greek: κάθισμα; Slavonic: каѳисма, kafisma), literally, "seat", is a division of the Psalter, used by Eastern Orthodox Christians and Eastern Catholics who follow the Byzantine Rite. The word may also describe a hymn sung at Matins, a seat used in monastic churches, or a type of monastic establishment.

According to ancient practice, monastics recite all 150 psalms on a regular basis. Originally, the hermits in the desert would recite the entire Psalter every day. With the spread of cenobitic monasticism, the practice began of chanting the Canonical Hours in common, and the Psalter thus became the foundation of the Daily Office, augmented by numerous hymns, prayers and scriptural readings. The custom grew of reciting all 150 psalms each week during the course of the services.

To facilitate this, the 150 psalms were divided into 20 sections, called kathismata (Greek: καθίσματα; Slavonic: каѳисмы, kafismy), meaning literally, "sittings". The name is derived from the fact that, in the Office as it developed in Jerusalem and Constantinople, the psalms would be read by one of the brethren while the others sat and listened attentively.

Each kathisma is further subdivided into three staseis (Greek: στάσεις), literally, "standings", because at the end of each stasis (Greek: στασις) the reader says: "Glory to the Father, and to the Son, and to the Holy Spirit..." at which all stand in honor of the Holy Trinity.

The Orthodox Church uses as its official version of the Old Testament, the ancient Septuagint (Greek) as opposed to the more recent Masoretic (Hebrew) recension. For this reason, the numbering of the psalms follows the Greek rather than the Hebrew (the King James Version of the Bible follows the Hebrew numbering). The difference in numbering can be determined from the following table:

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