al-Hasan al-Yusi

Muhammad al-Hasan ibn Masud al-Yusi (1040-1102H / 1631-1691 CE) was one of the most prominent Moroccan scholars of the 17th century, serving as professor at the Qarawiyyin and as a court scholar under multiple rulers. He is most famous for his bold letter (Qanun) to Sultan Moulay Ismail, rebuking him for oppression and reminding him of his obligations to justice — an act of scholarly courage that became legendary. He also wrote encyclopedic works on rhetoric, logic, Maliki fiqh, and natural sciences. His Muhadarat fi al-Adab wa al-Lughah is an encyclopedic collection on Arabic adab.