Little is known about Yefet b. 'Ali (or, as he is known by his Arabic name, Abu 'Ali Hasan b. 'Ali al-Lawi al-Basri1). The date of his birth in al-Basra is put at ca. 915 C.E.2 During the latter half of his life, he became attached to the ascetic ultra-pious community in Jerusalem known as the Avelei Zion or "mourners of Zion".3 His demise in Jerusalem is reckoned at ca. 1010,4 at a time when the Near Eastern Karaite community flourished. As a Biblical exegete, he is reported to have written a comprehensive Arabic commentary upon each and every Book of canonized O.T.,5 a gigantic literary feat.