What is the definition of 'extensive' sleep that invalidates ablution?
Chapter on What Nullifies Purification
Al-Mughni
Book of Purification
Primary text
The determination of 'extensive' sleep that invalidates ablution lacks a fixed limit, relying instead on custom. Some define the limit as when the sleeper changes their posture, such as falling onto the ground, or having a wet dream. The correct view is that there is no fixed limit because specification requires explicit textual prescription, which is absent here. Therefore, if evidence of extensiveness is found, such as the sleeper falling over, ablution is invalidated.
Supporting text
If one doubts whether the sleep was extensive, ablution is not invalidated because ritual purity is established with certainty and cannot be removed by doubt.