ومانع يمنع دوامه
An impediment that prevents the continuation of a ruling.
Here a legal effect has already arisen, but a recognized right of rescission or another relevant event can interfere with its persistence. The distinction from blocking commencement concerns the legal state: has the effect not yet arisen, or does an already existing effect become subject to termination?
The source lists options relating to puberty, emancipation, inspection of goods, lack of marital suitability, and healing in the law of injuries. Each needs to be understood in its own legal context rather than treated as an automatic, universal cancellation.