Twentieth Category: the mudraj (interpolated report)

This falls into several sub-types:

1. A prophetic hadith to which the transmitter, immediately after citing it, appends words of his own—or of someone else—and those who receive it from him relay the whole as one connected narration, imagining the addition to be part of the hadith.

2. The narrator possesses two distinct texts, each with its own chain, yet he relates them both through only one of those isnads.

3. He hears a hadith from several transmitters who differ over its chain or its wording, but he reports it from all of them as though they were in agreement.

All such practices are unlawful. Al-Khatib composed on this topic a monograph that is both comprehensive and sufficient. And Allah knows best.

Twenty-first Category: the mawduʿ (fabricated report)

This is the invented, concocted narration—the vilest form of weak hadith. It is impermissible to relate it knowingly, on any subject whatever, unless one clearly identifies it as such. Fabrication is established by the forger’s own confession—or something tantamount to it—or by an external indicator connected to the narrator or to the text itself. Many forged reports advertise their own falsehood through the feebleness of their wording or meaning. Abu’l-Faraj Ibn al-Jawzi, in roughly two volumes, compiled an extensive collection of such material; yet he included numerous items for which there is no proof of fabrication—reports that are merely weak, not forged.