ʿAbd Allāh ibn Abī Isḥāq al-Ḥaḍramī (d. 735-736 AD, 117 AH ). The efforts of three generations of grammarians culminated in the book of the Persian linguist Sibāwayhi (c. 760-793). Sibawayh made a detailed and professional description of Arabic in 760 in his monumental work, Al-kitab fi al-nahw (الكتاب في النحو,