He was reliable, truthful, and a veritable repository of knowledge.
Among those who transmitted from him were: Ahmad ibn Hanbal, Abū Thawr al-Kalbī, Abū Muhammad al-Dārimī, Salamah ibn Shabīb, Abū Bakr al-Athram, Abū Dāwūd, Muslim, Ismāʿīl Sammūyah, Muhammad ibn Yaḥyā al-Dhuhlī, Bishr ibn Mūsā, Muhammad ibn ʿAlī al-Ṣāʾigh, Abū Shuʿayb ʿAbd Allah ibn al-Ḥasan al-Ḥarrānī, Bahlūl ibn Isḥāq al-Anbārī, Abū Zurʿah al-Dimashqī, Abū Ḥātim al-Rāzī, ʿUthmān ibn Khurrāzādh, Abū al-Muwajjah Muhammad ibn ʿAmr al-Marwazī, al-ʿAbbās al-Asfāṭī, ʿAlī ibn ʿAbd al-ʿAzīz al-Baghawī, al-Ḥusayn ibn Isḥāq al-Tustarī, Khalaf ibn ʿAmr al-ʿUkbarī, Saʿīd ibn Masʿadah al-ʿAṭṭār, ʿUmayr ibn Mirdās, and many others.
Salamah ibn Shabīb said, “I mentioned Saʿīd ibn Manṣūr to Ahmad ibn Hanbal, and he spoke of him in the finest terms and exalted his stature.” (1)
Abū Ḥātim al-Rāzī stated, “He is trustworthy, one of the precise, firmly established authorities, and among those who collected and authored works.” (2)
Ḥarb al-Karmānī reported, “Saʿīd ibn Manṣūr dictated to us about ten thousand hadiths from memory.” (3)
I say: he was over eighty years old, perhaps even older.
He passed away in Mecca during Ramadan of the year 227 AH.
Whenever Muhammad ibn ʿAbd al-Raḥīm—nicknamed ‘the Thunderbolt,’ the ḥāfiẓ—narrated from Saʿīd, he would praise and commend him, saying, “Saʿīd ibn Manṣūr narrated to us, and he was firmly reliable.” (4)