namely, precision of the chest is achieved by preserving the report within one’s heart and keeping it firmly in mind, whereas precision of the book is attained by safeguarding one’s written copy until the moment it is read out or transmitted.

Grounds for impugning probity

With regard to probity (ʿadālah), there are five grounds on which a narrator may be discredited:
1 – proven lying,
2 – being accused of lying,
3 – flagrant sinfulness (fisq),
4 – obscurity (jahālah),
5 – heterodox innovation (bidʿah).

1 – Lying

By a narrator’s lying we mean that it has been established that he fabricated a prophetic report—either through the fabricator’s own admission or through other convincing evidence.

The fabricated report (mawḍūʿ)

Any narration that is impugned on the charge of lying is termed mawḍūʿ (fabricated).

The ruling on one who deliberately lies

If a person is proven to have deliberately lied in conveying hadith—even if it happened only once in his entire life—and even if he later repents, his narrations are never to be accepted. This differs from the false courtroom witness, whose testimony may be accepted after genuine repentance.