AS'AD AL-DIN, YA'ḲUB IBN ISḤAḲ AL-MAḤALLI:
Egyptian physician; lived in Cairo toward the end of the twelfth century and at the beginning of the thirteenth. He was born in al-MaḦallah, a city between Cairo and Damietta. Ibn Abi Usaibia, in his history of the Arabic physicians, praises As'ad highly and speaks of him as one of the most renowned scholars and physicians of that time. In 1201 As'ad went to Damascus, where he engaged in many controversies with the local physicians, among whom was Ṣadaḳa ben Munajjah, the Samaritan. He returned to Cairo, where he died.
Ibn Abi Usaibia mentions the following works of As'ad: (1) "Maḳalah fi Kawanîn Ṭabiyah" (Treatise on the Canons of Medicine); (2) "Kitab al-Nazh" (Book of Pleasure), on the reflection that the eye beholds in the mirror; (3) "Kitab fi Mizaj Dimashka" (Book Containing Three Treatises); (4) "Masail Ṭabiyah" (Questions of Medicine).
- Ibn abi Usaibia, ed. Müller, ii. 118;
- Carmoly, Histoire des Médecins, p. 71;
- Steinschneider, Hebr. Bibliographie, xv. 131.
