Kifāyat al-ʿĀbidīn · The Comprehensive Guide for the Servants of God

A vast Judeo-Arabic guide, of which only parts survive, setting out a pietist discipline for Egyptian Jewry: solitude, vigils, weeping, prostration, controlled breathing, a master-disciple relationship — and an explicit argument that these are the ways of the prophets of Israel, which the Sufis have kept and the Jews have forgotten.

The most remarkable single document in this annex. Not a scholar detecting influence centuries later — the head of a Jewish community stating in writing, to his own people, that the neighbours have preserved something that was ours. And his community fought him over it, all the way to the Muslim authorities.