This clearly establishes the certainty with which a single-chain report (khabar al-wāḥid) is to be accepted, and that no further verification is required; for had such a report failed to impart knowledge, the Qur’an would have commanded us to investigate it until certainty was reached. Further evidence is found in the consistent practice of the righteous predecessors and the leading scholars of Islam: they would habitually say, “The Messenger of Allah ﷺ said such-and-such, did such-and-such, commanded such-and-such, and forbade such-and-such.” This is self-evident throughout their speech. In Ṣaḥīḥ al-Bukhārī the phrase “The Messenger of Allah ﷺ said …” appears in many places, and in numerous ḥadiths a Companion states, “The Messenger of Allah ﷺ said …,” even though he had only heard it from another Companion. By doing so, the narrator is bearing witness and asserting with certainty that the Prophet ﷺ truly uttered or performed what he is attributing to him. If the solitary report did not yield knowledge, he would in effect be testifying about the Messenger of Allah without knowledge.

Fourth proof: the Prophetic practice and that of his Companions confirms reliance on solitary reports. The lived sunnah that the Prophet ﷺ and his Companions followed—during his lifetime and after his death—provides decisive proof that they made no distinction between a solitary report dealing with creed and one dealing with legal rulings; in every case it constituted binding evidence. I shall now, God willing, cite some of the authentic reports I have encountered. Imām al-Bukhārī (may Allah have mercy on him) records in his Ṣaḥīḥ, 8/132, under the heading: “Chapter: The permissibility of accepting the solitary report of a trustworthy narrator concerning the call to prayer, the prayer itself, fasting, obligatory duties, and legal rulings,” and he quotes the Almighty’s words: “Why should not a group from…"