Several prose genres arose to serve the needs of scholars studying the enormous body of Islamic religious literature. Among them were lexicography, grammar, and rhetoric—initially motivated by a desire to understand as fully as possible the language of the Qur'an. These investigations were initiated by Abu 'Amr ibn al-'Ala' (circa 689 - circa 770) of Basrah, one of the seven canonical "readers" of the Qur'an. These linguists studied the most ancient sources of Arabic, pre- Islamic poetry, alongside the Qur'an. They also investigated the speech of the Bedouin Arabs, which was considered the purest Arabic. The pioneer theorist and scholar of language in this effort was one of Abu 'Amr's students, Khalil ibn Ahmad (died between 776 and 791), who produced the first Arabic dictionary. The earliest Arabic surviving grammatical work is by Khalil's student Sibawayh (died circa 796). The extensive linguistic studies that followed made...