Typikon

typica; Greek: Τυπικόν, "that of the prescribed form"; Slavonic: Тvпико́нъ, сіесть уста́въ Tipikon or Ustav[1]) is a liturgical book which contains instructions about the order of the Byzantine Rite office and variable hymns of the Divine Liturgy.

The ancient and medieval cathedral rite of Constantinople, called the "asmatikē akolouthia" ("sung services"), is not well preserved and the earliest surviving manuscript dates from the middle of the eighth century.

In his Lausaic History, Palladius of Galatia, Bishop of Helenopolis, records that the early Christian hermits not only prayed the Psalms, but also sang hymns and recited prayers (often in combinations of twelve).

[2] With the rise of Cenobitic monasticism (i.e., living in a community under an Abbot, rather than as solitary hermits), the cycle of prayer became more fixed and complex, with different ritual practices in different places.

(XXV, 5) [3]The standardization of what became Byzantine monastic worship began with Saint Sabbas the Sanctified (439–532), who recorded the office as it was practiced at his time in the area around Jerusalem, passing on what had been handed down to him by St. Euthymius the Great (377–473) and St. Theoktistos (c. 467).