Is the report of water's impurity binding if given by a mature, sane, Muslim individual whose sinfulness is unknown?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
The report of water's impurity is obligatory to accept if delivered by an adult, sane Muslim whose sinfulness is not known. This applies whether the reporter is male or female, free or enslaved, or of known uprightness or merely of unknown moral standing. This acceptance is required because the report concerns a religious matter, akin to reporting the entry of the time for prayer, even if the specific cause of the impurity is not detailed.
Supporting text
The Qadi (Judge) holds that acceptance is not obligatory if the cause of impurity is not specified, due to the possibility that the reporter believes the water is impure due to a reason not accepted by the recipient (e.g., a Hanafi believing large amounts of water become impure, a Shafi'i believing small amounts of water become impure through contact with something lacking flowing blood, or an obsessive individual believing impurity arises from causes that normally do not cause impurity).