Ahmad bin Ghulamallah bin Ahmad bin Mahammad, Shihab al-Din al-Kum al-Rishi al-Qahiri () (1381 â 1432) was an Egyptian astronomer from Kum al-Rish region in Cairo. So, his nickname among astronomers became Al-Kum al-Rishi (). He is considered one of the greatest astronomers of his time, he worked in the art of the stars and began solving zij and writing calendars. He was appointed as a timekeeper at Al-Muayyad Mosque in Cairo.
He wrote very important books on astronomy, where he described the planets and stars accurately and explained their surfaces with great progress for his time.
His job as a âÂÂtimekeeperâ at Al-Muayyad Mosque gives him the advantage of combining âÂÂauthorship and practice,â between âÂÂknowledge and work.â Unfortunately, this job has been cut off from mosques in the Islamic world. Thus, only the âÂÂMuezzinâ was left, and in most cases he was not an astronomer or calendar scholar. Rather, the call to prayer was transformed into a daily job and the performance of a sufficient duty. But it lost the scientific mission assigned to it, which is to mobilize the Muslim's enthusiasm for universal intellectual scientific research and reach a state of creativity and leadership.
Ibn Hajar al-Asqalani (d. 852 AH/1449 AD), a contemporary of him and from the same country, who may have met him, said about him: âÂÂHe dabbled in the art of the stars and knew many rulings. He began to solve zij and write calendars, and he was one of the famous people in that.âÂÂ