His saying, “The most knowledgeable of them concerning the lawful and the unlawful is Mu‘ādh ibn Jabal,” is, by the agreement of hadith scholars, more likely to be authentic than his saying, “The best of you in judicial judgment is ‘Alī”—even supposing the latter were admissible as evidence. Since the former has a sounder chain of transmission and is clearer in its import, it follows that anyone who cites the latter as evidence that ‘Alī was more knowledgeable than Mu‘ādh ibn Jabal is ignorant. How much more so if he claims that ‘Alī was more knowledgeable than Abū Bakr and ‘Umar, both of whom were more knowledgeable than Mu‘ādh ibn Jabal! This is despite the fact that some scholars grade the hadith mentioning Mu‘ādh and Zayd as weak, while others grade it as good. As for the hadith mentioning ‘Alī, it is weak.

The hadith, “I am the city of knowledge,” is weaker and still more unsound. For this reason, it is counted among fabricated, falsely attributed reports, even though al-Tirmidhī narrated it. Accordingly, Ibn al-Jawzī included it in al-Mawdū‘āt (Fabricated Reports) and demonstrated that it is fabricated through all its chains of transmission. Its falsehood can be recognized from its very wording, without examining its chain of transmission.

For if the Prophet, may Allah bless him and grant him peace, were “the city of knowledge,” this city would have only one gate. Yet his teachings cannot have been conveyed by just one person. Rather, they must have been conveyed by transmitters numerous enough for their reports to establish certain knowledge for those who were not present. A single transmitter’s report does not yield certain knowledge unless accompanied by corroborating indications. Those indications may be absent, or they may be unknown to many or most people; consequently, those people would not attain certain knowledge of the Quran and the mass-transmitted Sunnah. This contrasts with mass transmission, which yields certain knowledge for the elite and ordinary people alike.

This hadith was fabricated by either a heretic or an ignorant person who thought it constituted praise. Yet it opens the way for heretics to impugn knowledge of the religion—since, on this account, only one Companion conveyed it.