The Sacramentary of Serapion of Thmuis is a work of Saint Serapion, or Sarapion (fl. ca. 330 to 360), bishop of Thmuis (Modern: "Tell el-Timai") in the Nile Delta and a prominent supporter of Athanasius in the struggle against Arianism (sometimes called, for his learning, Scholasticus). He is best known in connection with this prayer-book or sacramentary intended for the use of bishops.
The Sacramentary includes the earliest recorded use of the Sanctus.
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