The Sufficient Book (Kitāb al-kāfī)

Abū ’l-Faraj Hārūn, the leading student of Yūsuf ibn Nūḥ, succeeded his teacher as the head of the Karaite academy in Jerusalem. Abū ’l-Faraj composed numerous grammatical writings, not all of which survive, and was responsible for the abridgment of his teacher’s biblical commentary. Abū ’l-Faraj served as a conduit for many traditions of the Masoretes, and his scriptural insights, particularly his linguistic comments, were popular among eleventh- and twelfth-century Rabbanites living in al-Andalus (Muslim Spain). Byzantine Karaites, who translated his works into Hebrew, transmitted Abū ’l-Faraj’s writings to Europe.