Mā Shā’ Allāh ibn Athari () (c. 740–815 AD) was an 8th century Persian Jewish astrologer, astronomer, and mathematician. Originally from Khorasan he lived in Basra (present day Iraq) during the reigns of al-Manṣūr and al-Ma’mūn, and was among those who introduced astrology and astronomy to Baghdad in the late 8th and early 9th century. The bibliographer ibn al-Nadim in his Fihrist, described him "as virtuous and in his time a leader in the science of jurisprudence, i.e. the science of judgments of the stars". He served as a court astrologer for the Abbasid Caliphate and wrote numerous works on astrology in Arabic. Some Latin translations survive. The Arabic phrase indicates a believer's acceptance of God's ordainment of good or ill fortune. His name is probably an Arabic rendering of Hebrew Shiluh (), which is referenced in Genesis 49:10. Al-Nadim writes Mashallah's name Mīshā, meaning Yithru "Jethro" (). Latin translators called him many variants such as Messahala, Messahalla, Messala, Macellama, Macelarma, Messahalah, etc. The crater Messala on the Moon is named after him. Biography As a young man Mashallah participated in the founding of Baghdad for Caliph al-Manṣūr in 762 by working with a group of astrologers led by Naubakht the Persian to pick an electional horoscope for the founding of the city and building of an observatory. Attributed the author of over 20 titles, predominantly on astrology, his authority was established over the centuries in the Middle East, and later in the West, when horoscopic astrology was transmitted to Europe from the 12th century. His writings include both what would be recognized as traditional horary astrology and an earlier type of astrology which casts consultation charts to divine the client's intention. The strong influence of Hermes Trismegistus and Dorotheus is evident in his work. Works Listed in Kitab al-Fihrist The Big Book of Births () (14vols); The Twenty-One On Conjunctions, Religions and Sects (); The Projection of [Astrological] Rays (); The Meaning (); Construction and Operation of Astrolabes (); The Armillary Sphere (); Rains and Winds (); The Two Arrows (); Book known as The Seventh & Decimal (Ch.1 - The Beginning of Actions (); Ch.2 - Averting What Is Predestined (); Ch.3 - On Questions (); Ch.4 - Testimonies of the Stars (); Ch.5 - Happenings (); Ch.6 Movement and Indications of the Two Luminaries [sun & moon]) (); The Letters (); The Sultan (); The Journey ();