and other similar material.

Accordingly, when a report attributed to the Prophet (peace and blessings be upon him) is transmitted through two separate chains and we know that one transmitter did not take it from the other, we can be sure that it is sound—especially when the narrators involved are not of those who deliberately lie, and the only conceivable flaw lies in possible forgetfulness or error on the part of one of them.

Al-Ḥāfiẓ al-ʿAlāʾī quotes this last passage in Jāmiʿ al-Taḥṣīl (p. 38) and adds:

“Taken together the two chains raise the ḥadith to the rank of ḥasan, for the concern about weak memory in the narrators is thereby removed and each chain supports the other.”

The same point is made in Ibn al-Ṣalāḥ’s Introduction and in the abridgment prepared by Ibn Kathīr.

Ibn Taymiyyah—may Allah have mercy on him—further states (p. 352):

“In cases like this one benefits even from the narration of an unknown transmitter, from one whose retention is poor, from a mursal report, and the like. For that reason the scholars used to record such narrations, saying: ‘They are suitable as supporting evidence (shawāhid) and for cross-checking (iʿtibār) when nothing else serves that purpose.’”

He then cited Aḥmad’s earlier remark: “I may write down a man’s ḥadith so that I can compare it with others.”

I say: From all that has preceded the student of knowledge learns one of the key benefits behind the early ḥuffāẓ narrating aḥādīth with their full chains—even when some of those chains are weak—and then preserving them in their books: such material forms a primary reference point for corroboration, for tracing parallel and supporting chains that strengthen one another. Moreover, some of these narrations yield additional, sound pedagogical and practical insights.