sound owing to corroboration.

As for ḥasan in itself, its definition was given earlier 1: it is what is transmitted by an upright narrator of light precision, through a continuous chain, free from irregularity and any critical flaw.

ḥasan owing to corroboration, however, is the weak report whose lines of transmission multiply so that they mutually support one another; in that case it becomes ḥasan owing to corroboration. Why? Because if we examined each isnād individually it would not reach the rank of ḥasan, yet once they are considered together the report ascends to that rank.

A weak report, then, is simply that which is neither sound nor ḥasan.

All of these categories are acceptable—except the weak—and all are valid evidence—except the weak.

It is permissible to convey and recount every one of these categories to people, because they are all accepted and authoritative, save for the weak. A weak report may not be transmitted or mentioned unless its weakness is made clear, for whoever circulates a weak ḥadīth without clarifying its weakness is one of the two liars against the Prophet ﷺ. Muslim relates in his Ṣaḥīḥ that the Prophet ﷺ said, “Whoever narrates a report from me while he thinks it is false is one of the two liars.” 2 In another ḥadīth he said, “Whoever deliberately attributes a lie to me, let him take his seat in the Fire.” 3

Therefore, a weak ḥadīth may only be narrated on one condition: its weakness must be explained to the people. For instance, if someone relates a weak ḥadīth he should say, “It has been reported from the Prophet ﷺ …”