Abū Sahl al-Masīḥī, ʿĪsā b. Yaḥyā al-Masīḥī al-Jurjānī (d. after 400/1010), was a Persian polymath who wrote on physics, philosophy, astronomy and mathematics. There is little information on his life, with the only major source being Niẓāmī ʿArūḍī (pp. 118–121). Despite the fact that ʿArūḍī's account was repeated by later historians (Mīrkh^wānd, 7/465–466; Kh^wāndamīr, 2/444; Ghaffārī, 114–115) and has been relied on by many modern scholars, it is not entirel…