The author—may Allah have mercy on him—said:

24 – Whatever flaw is subtle or lies concealed, in their terminology is classed as muʿallal.

This is the twenty-fourth category of hadith set out in the poem: the muʿallal (also called the muʿall or the maʿlūl).

Hadith specialists employ three expressions: “al-ḥadith al-muʿallal,” “al-ḥadith al-muʿall,” and “al-ḥadith al-maʿlūl.” Linguistically, the form closest to correctness is “muʿall,” for its morphological pattern is mufʿal; the doubled lām counts as two consonants and the first is quiescent. From the standpoint of derivation this is precise, being taken from aʿallahu yuʿilluhu, so its passive participle is muʿall—just as aqarrahu yuqirruhu yields muqarr.

Those who say “maʿlūl” derive it from ʿillah, in the same way that shaddahu becomes mashdūd, and therefore call the report maʿlūl because it comes from the simple triliteral root.

Those who use “muʿallal” take it from ʿallalahu, hence muʿallal, just as qawwama becomes muqawwam. The preferred form, as noted, is muʿall.

Technically, a muʿall hadith is one whose outward appearance suggests soundness, yet closer scrutiny uncovers a hidden, damaging defect.

An example would be a report circulated as marfūʿ (traced back to the Prophet ﷺ) with a continuous chain. This is how it is commonly known among the hadith scholars. Then a ḥāfiẓ examines it and states: “This hadith contains a critical defect: the authorities actually transmitted it with a break in the chain.” Thus the real weakness is its discontinuity, even though the public assumes the isnād is uninterrupted.

Al-Ḥāfiẓ Ibn Ḥajar—may Allah have mercy on him—said in his commentary on al-Nukhba: “This category …”