is a Greek word the “teaching of the Apostles.” It was written in the second century. The of Nicomedia, Philotheus Bruennios, discovered it in 1883. The author of this text is likely to have been of Hebraic origins. Many Fathers of the such as Clement of Alexandria, Eusebius, and Athanasius used quotations from this book. Serapion, Bishop of Thmuis, quoted it in his liturgy.

In Egypt, the Oxhyrhynchus papyri contain the first two chapters of this book, and a Coptic translation of the text is preserved in the British Library. The unique complete manuscript was copied in the 11th century. The starts with a discussion of how one should live one’s life, then describes liturgical practices, prayers, and the Eucharist, and concludes with pastoral instructions.