Little is known about his life. He was probably born at the end of the 2nd century AH (791-816 AD). He lived and grew up in
Nishapur, as his
nisbah al-Azdi indicates; he belonged to the
Arab tribe of
Azd who settled in
Khorasan after the Muslim conquest. Al-Fadl and his family migrated to
Baghdad when he was young, where he began his education, and later relocated to the neighboring city of
Kufa, and then finally to
Wasit. Al-Fadl studied under prominent scholars such as Al-Ḥasan ibn Al-Faddal, Nasr ibn Muzahim, Safwan ibn Yahya and Hammad ibn Isa, and was also recorded to have been a disciple of the
Twelver Imam Ali al-Ridha. After spending years in Iraq, al-Fadl returned to Nishapur and continued his educational activities, until he was exiled by the
Tahirid governor for reportedly practicing Shi'ism. However, the sentence did not last for long. During his exile, he stayed in hiding in
Bayhaq, a town near Nishapur. While in hiding, he became ill, and eventually died in 873 or 874 AD. A mausoleum dedicated to him is located in Nishapur. ==Work==