علي بن موسى الرضا
The treatise is authored by Ali al-Ridha who was the seventh descendant of the Islamic prophet Muhammad and the eighth of the Twelve Imams. His given name was 'Alī ibn Mūsā ibn Ja'far. He was born in the house of Imam Musa al-Kadhim (the seventh Imam of Twelver Shia Islam) in Medina on the eleventh of Dhu al-Qi'dah, 148 AH (December 29, 765 CE). Ali al-Ridha was summoned to Khurasan and reluctantly accepted the role of successor to Ma'mun that was forced on him. He did not outlive Ma'mun, having been given poisoned grapes by him while accompanying him in Persia, and died at Tus on May 26, 818. Ali al-Ridha is buried within Imam Ridha Mosque, in Mashhad, Iran.