Abo‘l-Qasem al-Jonaid ibn Mohammad al- Khazzaz al-Nehawandi (d.298H/910CE)'alayhi al-rahmah wa'l ridwan

Abo‘l-Qasem al-Jonaid ibn Mohammad al- Khazzaz al-Nehawandi al-Baghdadi al-Shafi'i (d. 298) , son of a glass-merchant and nephew of Sari al-Saqati, close associate of al-Mohasebi, was the greatest exponent of the ‘sober’ school of Sufism and elaborated a theosophical doctrine which determined the whole course of orthodox mysticism in Islam. He expounded his theories in his teachings, and in a series of letters written to various contemporaries which have survived. The head of a large and influential school, he died in Baghdad in 298 (910).