Ibn Abī al-Dunyā said: “I was informed by Mūsā ibn Dāwūd, who related, ‘I have never seen anyone with a sharper memory than ʿAlī ibn al-Jaʿd. We were in the company of Ibn Abī Dhīʾb when he dictated twenty hadiths to us; ʿAlī memorized them on the spot and then recited them back to us.’” (1)

Ṣāliḥ ibn Muḥammad reported: “I heard Khalaf ibn Sālim say, ‘Aḥmad ibn Ḥanbal, Ibn Maʿīn, and I once went to ʿAlī ibn al-Jaʿd. He brought out his notebooks, set them before us, and walked off. We assumed he had gone to prepare a meal for us. While he was away we reviewed his books and discovered only a single error. After we had finished eating, he returned and said, “Hand them over,” whereupon he narrated—purely from memory—everything we had written down.’” (2)

ʿAbd al-Khāliq ibn Manṣūr said: “I heard Yaḥyā ibn Maʿīn remark, ‘I have been writing down hadith from ʿAlī ibn al-Jaʿd for more than thirty years.’ He made this statement in 225 AH.” (3)

Al-Baghawī said: “I heard ʿAlī ibn al-Jaʿd say, ‘I copied hadith from Sufyān ibn ʿUyaynah in 160 AH, in Kūfah; he dictated to us from a written scroll.’” (4)

Khalaf ibn Muḥammad al-Khayyām recounted: “I heard Ṣāliḥ ibn Muḥammad say, ‘Whenever ʿAlī ibn al-Jaʿd narrated from Shuʿbah he would give each person only three hadiths, and all that he possessed from Mālik amounted to three hadiths.’” (5)

Al-Ḥusayn ibn Ismāʿīl al-Fārisī said: “I asked ʿAbdūs ibn Hāniʾ about—”