Dāwūd ibn al-Ḥusayn al-Bayhaqī said: I heard Isḥāq al-Ḥanẓalī, and he was asked about the congregational prayer: “Is it obligatory?” He replied, “Yes.” (1)

ʿAbd Allah ibn Abī al-Khuwārizmī reported: I heard Isḥāq al-Ḥanẓalī say, “Khurasan has produced three men unrivalled for their innovation in religion and for their lies: Jahm, ʿUmar ibn Ṣubayḥ, and Muqātil.”

Muḥammad ibn Ṣāliḥ ibn Hāniʾ said: I heard Ibrāhīm ibn Muḥammad al-Ṣaydalānī relate, “I was in Isḥāq’s gathering when Salamah ibn Shabīb asked him about someone who narrates ḥadith for payment. He answered, ‘Do not write from him.’ ”

Ḥakkām ibn Salm narrated to us, from al-Rabīʿ ibn Anas, from Abū al-ʿĀliyah, who said, “It is written in the scriptures: ‘Teach free of charge just as you were taught free of charge.’ ”

In the handwriting of Abū ʿAmr al-Mustamlī: I heard Abū Aḥmad Muḥammad ibn ʿAbd al-Wahhāb say, “I heard Isḥāq ibn Ibrāhīm, and he was asked about a man who omits the phrase bismi-llāh al-raḥmān al-raḥīm (In the name of Allah, the Most Compassionate, the Most Merciful). He replied, ‘Whoever leaves out the B, or the S, or the M of it, his prayer is invalid, because al-Ḥamd—that is, Sūrat al-Fātiḥah—consists of seven verses.’ ”

Ibn al-Mubārak said, “Whoever leaves it out has discarded one hundred and thirteen verses of Allah’s Book, exalted is He.”

Al-Ḥākim remarked, “Isḥāq ibn Rāhwayh was the leading authority of his age in memorization and legal verdicts. He settled in Naysābūr and died there.

“It is also said that he was originally from Marw and that he travelled to Iraq in—”