Bakr, son of the chief-judge, the Imām Abū Mūsā, a Shāfiʿī jurist who served as judge of Nīshāpūr and later of Ahwāz.

He was born a few years after 200 AH.

He narrated from Qālūn, ʿĪsā ibn Mīnā—Mūsā was the very last of Qālūn’s pupils—as well as from Aḥmad ibn Yūnus al-Yarbūʿī, ʿAlī ibn al-Jaʿd, ʿAlī ibn al-Madīnī, Yaḥyā ibn Bishr al-Ḥarīrī, Abū Naṣr al-Tammār, his own father Isḥāq al-Khaṭmī, and many others.

Among those who transmitted from him were ʿAbd al-Bāqī ibn Qāniʿ, Ḥabīb al-Qazzāz, Abū Muḥammad ibn Māsī, and a number of others.

Ibn Abī Ḥātim said: “I wrote down ḥadiths from him; he is trustworthy and truthful.” (1)

His son Aḥmad related: “My father said, ‘I heard 300,000 ḥadiths from Abū Kuraib.’”

Aḥmad ibn Kāmil said: “He was eloquent, had listened extensively, was commendable, and inclined toward the school of al-Shāfiʿī.” (2)

Ibn al-Munādī said: “I was informed that he began teaching people the Qur’an when he was eighteen years old.” (3)

It is reported that the caliph al-Muʿtaḍid instructed his vizier to look after Ismāʿīl the judge and Mūsā ibn Isḥāq, saying, “Through these two the people of the earth are protected.” (4)