ومانع يمنع ابتداء الحكم
An impediment preventing the initial commencement of a ruling.
At this stage the legal basis is recognized, but a further legal factor blocks the intended effect from taking immediate operation. This is different from a nonconstituted or incomplete operative cause.
The central question becomes: assuming the relevant contractual or legal basis exists, what additional right or circumstance prevents the expected legal effect from beginning now? The source illustrates this with an option stipulated in a sale and the continuing prayer time of an excused person.