Tenth Principle: A hadith is not automatically strengthened merely because it has many chains of transmission.

It is well known among the scholars that when a report reaches us through several routes it can, by their convergence, gain strength and become acceptable evidence, even though each individual chain is weak. This, however, is not an absolute rule. The rigorous critics restrict it to cases in which the weakness in those various chains stems from the narrators’ poor memory, not from any doubt about their honesty or their religious integrity. If the defect lies in their truthfulness or uprightness, the hadith is never strengthened, no matter how numerous its routes.

This qualification is cited by the meticulous scholar al-Manāwī in Fayḍ al-Qadīr, quoting the verdict of the scholars:

“When the weakness is severe, it is not remedied by the report’s appearance through another route, even if the chains are many. Hence they all agreed on the weakness of the hadith, ‘Whoever preserves for my community forty hadiths’ 1 despite its abundance of chains, because its weakness is grave and the supporting routes are incapable of repairing it. By contrast, when the weakness is slight and the corroborating chain is not too deficient, it can indeed be mended and reinforced.”

See further: Qawāʿid al-Taḥdīth, p. 90; Sharḥ al-Nukhbah, p. 25.

Accordingly, anyone who wishes to bolster a hadith by citing its multiple chains must first examine