Abu Ya`la al-Ja`fari
Abu Ya`la al-Ja`fari (d. 463/1071), a contemporary of al-Tusi and al-Najashi, and an eminent pupil of al-Mufid, was also al-Mufid's son-in-law. Al-Najashi gives the following account of him: Abu Ya`la Muhammad b. al-Hasan b. Hamza al-Ja`fari, successor of Shaykh Abu `Abd Allah b. Nu`man (al-Mufid), who occupies his teacher's chair and delivers lectures, is a mutakallim, a faqih, and has many books to his credit.
In Rijal al-Najashi it is mentioned that Abu Ya`la died on the 16th of Ramadan 463/1071. As al-Najashi himself expired in 450/1058, the date of Abu Ya`la's death in his book should have been entered by one of al-Najashi's pupils or a scribe. Abu Ya`la's rise to his teacher's post in the presence of scores of eminent scholars among al-Mufid's pupils is astonishing and is indicative of his high status as a scholar. It is most probable that Abu Ya`la did not succeed his teacher soon after his death, for at that time Abu Ya`la's age should have been about thirty and it was improbable that he could occupy al-Mufid's place after a considerable gap of time.
According to Qamus al-rijal, it is written in `Umdat al-talib that Abu Ya`la was a descendant of Ja`far al-Tayyar b. Abi Talib, an elder brother of Amir al-Mu'minin `Ali.In later books of rijal, also Abu Ya`la is mentioned as an eminent faqih who trained a number of outstanding scholars.