Ibn Hajar al-ʿAsqalani (d. 1449) was a medieval polymath—an innovative religious commentator, a historian and biographer, a judge on the highest court in Cairo, an author of spiritual poetry, and a textile trader from a powerful family of spice merchants. His masterpiece is a twelve-volume commentary on prophetic traditions called Fath al-Bari (Unlocking the Divine Wisdom), parts of which he incorporated into Merits of the Plague.
