Abu Ahmad al-Marwazi: Declared him trustworthy
Abu al-Faraj ibn al-Jawzi: He accused him of fabrication. Ibn Hajar said: They are mistaken in that, and he was severely confused with another narrator
Abu Ja'far al-'Uqayli: Declared him trustworthy
Abu Hatim al-Razi: Truthful, there is no problem with him, his hadith is not cited as evidence
Abu Dawud al-Sijistani: Trustworthy
Ahmad ibn Hanbal: There is no problem with him, and he was an intelligent, religious man, and I saw him coming out from Harun's place wearing black
Ahmad ibn Shu'ayb al-Nasa'i: Trustworthy
Ahmad ibn Salih al-Jili: Declared him trustworthy
Ahmad ibn Ya'qub al-Halabi: Trustworthy, Truthful
Ibn Hajar al-'Asqalani: Trustworthy, he may have made mistakes. Ibn Hibban went too far in criticizing him, saying he deserves to be abandoned. And once: Abu Hatim criticized him with leniency
Ibn Qutaybah al-Dinawari: Declared him trustworthy
Al-Dhahabi: Trustworthy, one of the scholars of Basra
Sulaiman ibn Harb al-Azdi: He died six months before Hammad ibn Zayd. Ibn Abi al-Aswad said: Hammad ibn Zayd died in the year one hundred and ninety-nine
Abd al-Rahman ibn Yusuf ibn Kharash: Trustworthy
Ali ibn al-Madini: He was an old man, trustworthy
Muhammad ibn Jarir al-Tabari: Trustworthy, but he sometimes made mistakes in what he narrated
Muhammad ibn Sa'd, the scribe of al-Waqidi: Trustworthy, and he may have made mistakes. And once: He was not strong in hadith
Muhammad ibn 'Ammar al-Mawsili: I did not know him, he was a man from the nobles of Muhallab
Authors of Tahrir Taqrib al-Tahdhib: Trustworthy, and there is no point in mentioning 'he may have made mistakes' because it has no meaning, as the Imams have declared him trustworthy
Nasr ibn Ali al-Jahdami: He said: Ali ibn al-Madini came to me and said: Let us go to Muhammad ibn Abbad so that we can look at his father's book about Shu'bah
Hisham ibn 'Ammar al-Dimashqi: I did not know him, he was a man from the nobles of Muhallab
Yahya ibn Ma'in: Trustworthy, once Abbad ibn al-'Awwam and Abbad ibn Abbad both are trustworthy, and Abbad ibn Abbad is the most trustworthy and the most narrated of them
Ya'qub ibn Shaybah al-Sadusi: Trustworthy