Abu Musa said: Abu Ghalib Hibat Allah ibn Muhammad ibn Harun recorded in his own handwriting, saying, “I heard some of the hadith scholars relate that a transmitter once came before the judge, Abu Ahmad, and said, ‘I have sworn an oath that you have memorised seventy thousand hadiths; is my oath valid?’ He replied, ‘Your oath is valid. I have memorised, with regard to the Qur’an, seventy thousand hadiths.’

People also say that he dictated a lengthy tafsir entirely from memory, and that he once dictated forty thousand hadiths in Ardistan. When he returned to Isfahan, he compared the text with his notes and found it exactly as he had dictated.

A group informed us in writing; al-Kindi informed us; al-Shaybani informed us; al-Khatib informed us; ʿAbd Allah ibn Ahmad ibn ʿAli al-Sawdhurjani—who was devout and reliable—told me: I heard Ibn Manda say, “I wrote from one thousand shaykhs, and I found none more exact than Abu Ahmad al-ʿAssal.”

Yahya ibn Manda said: I heard my uncle say, I heard my father say, “I wrote from one thousand seven hundred shaykhs, yet I found none like Abu Ahmad al-ʿAssal and Ibrahim ibn Muhammad ibn Hamzah.” The same was transmitted by Ahmad ibn Jaʿfar al-Faqih from Abu ʿAbd Allah, who likewise said, “One thousand and seven hundred.”

And Ibn Manda said, “I travelled through the world twice, and I never saw anyone comparable to al-ʿAssal.”

Abu Ghalib also reported that al-ʿAssal never sat to dictate hadith, nor did he touch a book-section, except in a state of ritual purity; and that, on one occasion while he was with his son-in-law, he entered a mosque, began the prayer, and completed the entire Qur’an in a single rakʿah.

Abu Ghalib said: I heard my grandfather say, ‘I heard my father, Abu Ishaq Ibrahim, son of the judge Abu Ahmad al-ʿAssal, relate: When the judge died and his sons sat to receive condolences, two men dressed in black entered and began wailing…’