What action must be taken if the gap in memory (fasil) after prematurely saluting is prolonged?

Primary text

If the person does not remember the omission until a prolonged separation of time has passed, or if their ablution is nullified, they must restart the entire prayer anew. This applies equally to the view of ash-Shafi'i for a short delay resembling the case of Dhu al-Yadayn, and to the view of Malik. This is based on the principle that a prayer cannot be built upon another after a long separation, analogous to the nullification of ablution.