ʿAlī ibn al-Madīnī reported from Yaḥyā al-Qaṭṭān, who said, “Ibn ʿUlayyah is more reliable than Wuhaib.”

Ibn Mahdī said, “He is more dependable than Hushaym.”

ʿAffān related: “We were with Ḥammād ibn Salamah when he erred in a hadith. He was a man who never retracted to anyone’s opinion, so it was said to him, ‘You have been contradicted in this matter.’ He asked, ‘By whom?’ They replied, ‘Ḥammād ibn Zayd,’ but he took no notice. Then they said, ‘Ismāʿīl ibn ʿUlayyah is at odds with you.’ At that he rose, went inside, came back out, and declared, ‘The correct view is what Ismāʿīl has said.’”

ʿAbd Allāh ibn Aḥmad ibn Ḥanbal narrated from his father: “With regard to meticulous verification in Basra, the matter ends with him—that is, with Ismāʿīl.”

He also quoted his father as saying: “I missed the chance to meet Mālik, and Allah compensated me with Sufyān ibn ʿUyaynah; I missed Ḥammād ibn Zayd, and Allah compensated me with Ismāʿīl ibn ʿUlayyah. Ḥammād ibn Zayd was untroubled about contradicting Wuhaib and al-Thaqafī, but he was apprehensive of opposing Ismāʿīl whenever their reports differed.”

Muslim recorded the same statement from Aḥmad ibn Ḥanbal.

Abū Bakr ibn Abī al-Aswad said, “From the very first day I entered the field of hadith, no one was ever placed ahead of Ismāʿīl ibn ʿUlayyah.”

Aḥmad ibn Muḥammad ibn Muḥriz transmitted from Yaḥyā ibn Maʿīn: “Ismāʿīl was trustworthy, reliable, truthful, a sincere Muslim, scrupulous, and God-fearing.”

Qutaybah said, “People used to say, ‘The four master preservers are: Ismāʿīl, Wuhaib, ʿAbd al-Wārith, and Yazīd ibn Zurayʿ.’”

Yaʿqūb al-Sadūsī narrated on the authority of al-Haytham ibn Khālid: “The hadith masters gathered …”