Searchable Online Version Al-Khalīl b. Aḥmad al-Farāhīdī, Kitāb al-ʿAin كتاب العين للخليل بن أحمد الفراهيدي

Kitāb al-ʿAin is the first dictionary of the Arabic language ever written. It was written by al-Khalīl b. Aḥmad (died 786 CE / 170 AH) and organized by his friend and student the scholar al-Layth bin Muẓaffar al-Kinānī (al-Azharī considers al-Kinānī the true writer of Kitāb al-ʿAin). Kitāb al-ʿAin is one of the foundational texts of Arabic linguistics, as it is a primary source that does not depend on other texts, but on the vast knowledge of the writer himself. Al-Khalīl acted as a teacher to some of the greatest scholars of the Arabic language, including Sībawayh, al-Aṣmaʿī, al-Kisāʾī, Hārūn bin Mūsā al-Naḥwī, Wahb bin Jurayr and al-Juhdhumī.