«والمانع: ما يحول دون ترتب الحكم مع وجود السبب»
A mani is a factor that prevents a ruling from taking effect despite the presence of its occasion.
The book illustrates this with inheritance: kinship is relevant, but killing can operate as an impediment to inheriting in specified legal circumstances. The presence of kinship does not make every consequent entitlement automatic.
A complete analysis therefore asks not only whether a relevant sabab exists, but also whether a legally recognized impediment is present.