Among those who narrated from him were: Muḥammad ibn Sīrīn—who in fact counted him among his own teachers—al-Zuhrī, Qatādah, and Ṣafwān ibn Sulaym, who were his contemporaries; Manṣūr, al-Aʿmash, Zayd ibn Abī Unaysah, Zakariyyā ibn Abī Zāʾidah, Misʿar, Sufyān, Mālik ibn Mighwal, Shuʿbah ibn al-Ḥajjāj; his son Yūnus ibn Abī Isḥāq; his grandson Isrāʾīl; Zāʾidah ibn Qudāmah; Ismāʿīl ibn Abī Khālid; Ashʿath ibn Sawwār; al-Masʿūdī; ʿAmmār ibn Zurayq; al-Ḥusayn ibn Wāqid; al-Ḥasan ibn Ṣāliḥ ibn Ḥayy; Ibrāhīm ibn Ṭahmān; Abū Wakīʿ al-Jarrāḥ ibn Malīḥ; Jarīr ibn Ḥāzim; Ḥamzah al-Zayyāt; Fiṭr ibn Khalīfah; Waraqāʾ ibn ʿUmar; Shuʿayb ibn Ṣafwān; Shuʿayb ibn Khālid; Raqabah ibn Maṣqalah; Zuhayr ibn Muʿāwiyah and his brother Ḥudayj ibn Muʿāwiyah; Abū ʿAwānah al-Waḍḍāḥ; Sharīk the judge; Abū al-Aḥwaṣ Sallām ibn Sulaym; Abū Bakr ibn ʿAyyāsh; Sufyān ibn ʿUyaynah, and a great many others.

He is unanimously regarded as reliable, an authoritative proof with no dissent.

When he reached advanced age his retention weakened in the normal way, yet he never became confused.

Ḥamzah ibn Ḥabīb recited the Qurʾān to him by presentation, making Abū Isḥāq the senior-most of Ḥamzah’s teachers in the Book of Allah, exalted be He. Abū Isḥāq also took part in a campaign against the Byzantines during Muʿāwiyah’s rule.

He said, “Muʿāwiyah asked me, ‘What was your father’s monthly stipend?’ I answered, ‘Three hundred.’ So he assigned the same allowance to me.”

I (the author) say: What a generous favor that was! In earlier and later times alike, if a cavalryman receives three hundred dirhams a month in addition to his share of the booty, that is a sizeable gift.

ʿAlī ibn al-Madīnī said, “Abū Isḥāq narrated from seventy—or eighty—people from whom no one else narrated, and the tally of his teachers came to about three hundred.”

In another place ʿAlī said, “Four hundred teachers.”

It was also said that he heard from thirty-eight Companions.

Abū Ḥātim remarked, “In the abundance of his narrations he resembles al-Zuhrī.”

Al-Aʿmash said, “Whenever the companions of Ibn Masʿūd saw Abū Isḥāq they would say, ‘This is ʿAmr the reciter who never turns his head.’ ”

Ibn Fuḍayl reports from his father: “Abū Isḥāq used to complete a recitation of the Qurʾān every three days.”