and Isḥāq ibn Muḥammad al-Zayyāt; Jaʿfar ibn Abī Bakr; Ismāʿīl ibn al-ʿAbbās al-Warrāq; al-Ḥusayn ibn Ismāʿīl al-Maḥāmilī—and his brother Abū ʿUbayd al-Qāsim; Abū al-ʿAbbās ibn ʿUqda; Muḥammad ibn Makhlad al-ʿAṭṭār; Abū Ṣāliḥ ʿAbd al-Raḥmān ibn Saʿīd al-Aṣbahānī; Muḥammad ibn Ibrāhīm ibn Ḥafṣ; Jaʿfar ibn Muḥammad ibn Yaʿqūb al-Ṣaydalī; Abū Ṭālib Aḥmad ibn Naṣr, the ḥāfiẓ; al-Ḥusayn ibn Yaḥyā ibn ʿAyyāsh; Muḥammad ibn Sahl ibn al-Fuḍayl; Aḥmad ibn ʿAbd Allāh, the agent of Abū Ṣakhrah; Aḥmad ibn Muḥammad ibn Abī Bakr al-Wāsiṭī; al-Ḥusayn ibn Muḥammad al-Muṭbaqī; Abū Jaʿfar ibn al-Bakhtarī; Ismāʿīl al-Ṣaffār, and countless others.
He in turn narrated to Abū Bakr al-Shāfiʿī and to Ibn al-Muẓaffar. In middle age he travelled to Syria and Egypt, where he heard hadith from Ibn Ḥayyūyah al-Naysābūrī, Abū al-Ṭāhir al-Dhuhlī, Abū Aḥmad ibn al-Nāṣiḥ, and many more.
He was an ocean of knowledge, one of the foremost Imams of his era; the pinnacle of memorisation, the science of hidden defects, and expertise in transmitters ended with him. He was likewise pre-eminent in the Qurʾānic readings and their routes, and enjoyed strong command of jurisprudence, points of legal disagreement, the prophetic expeditions, historical battles, and much else.
Abū ʿAbd Allāh al-Ḥākim said in his book Muzakkī al-Akhbār: “Abū al-Ḥasan became the unique scholar of his age in retention, understanding, and piety, an imam for the Qurʾān reciters and the grammarians. When I first entered Baghdad he used to attend the gatherings while still under thirty years of age, yet he was already one of the ḥuffāẓ.”
I say: al-Ḥākim was mistaken, for he did not enter Baghdad until 341 AH, and Abū al-Ḥasan was then thirty-five years old.
He produced numerous works and his fame spread across the world. He was the first to compile a systematic book on the variant readings, arranging its chapters before treating the individual letters.