He adhered to Muʿtazilism, and in Hamadhān he studied under Abū Ṭāhir ibn Salamah; in Iṣfahān he learned from Abū Nuʿaym; in Harrān from Abū al-Qāsim al-Zaydī; and from a number of other scholars besides.

Among those who transmitted from him were Abū al-Qāsim ibn al-Samarkandī, Abū Ghālib ibn al-Bannāʾ, Hibat Allāh ibn Ṭāwūs, Maḥmūd ibn Muḥammad al-Rahabī, the ḥadith master Ismāʿīl ibn Muḥammad al-Taymī, Abū Bakr Muḥammad ibn ʿAbd al-Bāqī, Abū Saʿd ibn al-Baghdādī, and others.

Al-Samʿānī said: “He was one of the leading men of letters. He compiled the Great Tafsīr, a commentary the like of which has never been seen—none larger, nor richer in benefit—were it not that he blended it with Muʿtazilite doctrine, disseminated his creed in it, and failed to follow the path of the early generations. He remained in Egypt for years, gathered loads of books, then conveyed them to Baghdad, and he was an open advocate of Muʿtazilism (1).”

Ibn ʿAsākir said: “He lived in Tripoli for a time.”

I heard al-Ḥusayn ibn Muḥammad al-Balkhī say: “Abū Yūsuf composed his Tafsīr in a little over three hundred volumes (2).” He added, “Whoever reads it to me, I shall give him the manuscript,” yet no one ever read it.

Hibat Allāh ibn Ṭāwūs related: “I visited him when he had become incapacitated. He asked, ‘Where are you from?’ I replied, ‘From Damascus.’ He said, ‘The land of nasb (hostility toward the Prophet’s Household) (3).’”

Ibn ʿAsākir also said: “It is reported that Ibn al-Barrāj, the head of the Rāfiḍite sect in Tripoli, once asked him:”