Abu Hatim al-Razi: Truthful
Abu Dawud al-Sijistani: He did not criticize men and was knowledgeable about them, and he did not use his knowledge
Abu Isa al-Tirmidhi: He was a Hadith preserver
Abu Ya'la al-Khalili: He resembled Ahmad in his appearance and piety
Ahmad ibn Hanbal: I did not know him to seek Hadith nor did I see him seeking Hadith, and once: He did not praise him and once the people of the frontier mentioned him to him, not satisfied or words to that effect
Ahmad ibn Shu'ayb al-Nasa'i: Trustworthy
Ibn Hajar al-Asqalani: Trustworthy Hadith preserver with compilations, once: Ahmad criticized him because of Kalam
Al-Khatib al-Baghdadi: Trustworthy Hadith preserver
Al-Dhahabi: Sound authority
Dawud ibn al-Husayn al-Bayhaqi: It reached me that al-Hulwani al-Hasan ibn Ali said, 'I do not declare anyone who pauses in the Quran as a disbeliever,' so they abandoned his knowledge
Salamah ibn Shabib al-Naysaburi: He was asked about his knowledge, so he said, 'He throws into the thicket, and whoever does not witness the disbelief of the disbeliever is a disbeliever,' because he did not declare those who say the Quran is created as disbelievers, and al-Hasan himself says it is the word of Allah, uncreated, we know nothing but this
Abdullah ibn Ahmad ibn Hanbal: I only know that he came to me here to greet me and said, 'Things reach me about him that I dislike,' and I did not see him take him lightly
Muslimah ibn al-Qasim al-Andalusi: He deemed him trustworthy
Ya'qub ibn Shaybah al-Sadusi: He was trustworthy, sound, and precise, and once: A possessor of sound Hadith, knowledgeable in jurisprudence