«النقض: هو بيان تخلف الحكم عن العلة»
Naqd identifies a case in which the alleged cause is present but the claimed ruling does not follow.
The author’s example concerns ablution, dry ablution and the role of intention. A proposed cause claimed to hold across acts of purification may be challenged by another act in which the legal outcome differs.
For the counterexample to be decisive, the proposed cause must genuinely apply to the counterexample; otherwise the cases may simply be materially different.