Abu Hatim al-Razi: Shaykh, not bad
Abu Dawud al-Sijistani: He is nothing
Ahmad ibn Shu'ayb al-Nasa'i: Not trustworthy
Ibn Hajar al-'Asqalani: Truthful, very important
Muhammad ibn Auf al-Hamsi: I have no doubt that Isaac ibn Zubayriq is a liar
Yahya ibn Ma'in: The young man is not bad and he praised him well