Abū al-Jaysh al-Balkhī, Muẓaffar b. Muḥammad b. Aḥmad al-Khurāsānī (d. 367/978), was an Imāmī theologian (mutakallim) and traditionist (muḥaddith). Nothing is known about his date of birth. He studied under Muḥammad b. Jarīr al-Ṭabarī (d. 310/922) and Abū Sahl al-Nawbakhtī (d. 311/923) (al-Najāshī, 422; al-Ṭūsī, Amālī, 1/250; idem, al-Fihrist, 169). In addition to the two scholars mentioned he also studied under, and heard ḥadīths from, other scholars in Baghdad such as Ibn Humām al-Iskāfī, Muḥammad b. Aḥmad b. Abī al-Thalj and Muḥammad b. Jaʿfar al-ʿAlawī al-Ḥusaynī (al-Mufīd, al…