Siddur of Saadia Gaon

The Siddur (prayerbook) of Saadia Gaon is the first known attempt to transcribe the weekly ritual of Jewish prayers for week-days, Sabbaths, and festivals. The text also contains liturgical poetry by Saadia, as well as Arabic language commentary. There is no known extant manuscript of the entire text, though there is a near complete manuscript in Oxford. Fragments have also been found in the Cairo Genizah[?]. The prayerbook apparently served as a basis for later efforts to codify the Jewish prayer ritual and set it down in writing and was imitated by later authors.