Question:
Respected Brother Baqir,
Peace, mercy, and blessings of Allah be upon you.
It has been reported from Shaykh al-Najashi regarding al-Mufaddal ibn Umar, the following:
\"Al-Mufaddal ibn Umar, Abu Abdullah — and it is said Abu Muhammad al-Juʿfi — a Kufan, was of corrupt belief, unreliable in narration, and not taken into account. It is said he was a Khattabi (a follower of Abu al-Khattab). Some works are attributed to him, but they are not dependable.\"
[Rijāl al-Najāshī, p. 416]
The scholar Sayyid al-Khū’ī (may his secret be sanctified) thoroughly examined the statements of all the scholars of biographical evaluation (rijāl) regarding al-Mufaddal ibn Umar, and reviewed them in his book “Muʿjam Rijāl al-Ḥadīth.” He then explicitly stated:
\"What can be concluded from what we have mentioned is that the attribution of Ghulāt beliefs (exaggeration) and affiliation with the Khattabi sect to al-Mufaddal ibn Umar has not been firmly established. Although this attribution is mentioned in the book ascribed to Ibn al-Ghaḍā’irī, the attribution of the book itself to him is not proven, as has been indicated several times. And although the statement of al-Kashshi appears to suggest that al-Mufaddal was initially upright and later became a Khattabi, there is no conclusive evidence for that. Najashi’s own wording, where he says \'It is said he was a Khattabi,\' implies his own reservation and that it was merely a report from some person.\"
\"As for the narrations that were mentioned in criticism of him, those with weak chains of transmission are not considered. True, three of them have complete chains of narration, but even then, their interpretation must be referred to the experts, as they cannot outweigh the numerous corroborative narrations that were likely issued by the Imams in general. Among them are narrations with authentic chains of transmission. Thus, these critical narrations must be interpreted just like the narrations that criticize Zurarah, Muhammad ibn Muslim, Yazid ibn Muʿawiyah, and their peers.\"
\"What confirms this is that the conflicting reports are only from Imam al-Sādiq (peace be upon him), whereas the narrations from Imam al-Kāẓim and Imam al-Riḍā (peace be upon them both) are all in his praise, as has been mentioned earlier. This indicates that the criticism attributed to Imam al-Sādiq (peace be upon him) was for a specific reason.\"
\"And it is sufficient in proving the noble status of al-Mufaddal that Imam al-Sādiq (peace be upon him) entrusted him with his famous book Tawḥīd al-Mufaddal (Monotheism of al-Mufaddal), which Najāshī referred to as Kitāb Fikr (Book of Thought) — a clear indication that al-Mufaddal was among his close companions and the object of his attention.\"
\"In addition to this is the explicit endorsement of him by Shaykh al-Mufīd, who counted him among the righteous jurists and among the close companions of Imam al-Sādiq (peace be upon him), as well as the trustworthy agents. As for Najāshī’s statement that he had \'corrupt belief, unreliable narration, not to be relied upon, and had works not depended upon,\' this requires elaboration:\"
Najāshī’s saying: “he had corrupt belief” is contradicted by what Shaykh al-Mufīd stated about him being among the righteous jurists and close companions of Imam al-Sādiq (peace be upon him). Therefore, the statement of Shaykh al-Mufīd should be preferred, especially as it is supported by multiple narrations, from which general reliability can be inferred.
As for Najāshī’s statement that he was “unreliable in narration,” even if it were correct, it does not prove that he was untrustworthy, as has already been explained in the case of al-Muʿallā ibn Muhammad al-Baṣrī.
As for the statement that “he had books that were not relied upon,” this is based on the assumption that he was of corrupt belief and unreliable, which, as you have seen, is not the case. Furthermore, it appears that Najāshī himself was not certain that these books were actually authored by al-Mufaddal. He merely reported what was said, and the transmission chains to those books are weak.
Conclusion:
Al-Mufaddal ibn Umar was a dignified and trustworthy figure. And Allah knows best.
[Muʿjam Rijāl al-Ḥadīth, vol19, P317–330]
May you remain safe and in Allah’s protection.