Usefulness of the Prophet in awakening

A benefit narrated that the Prophet, may God’s prayers and peace be upon him, said : If one of you wakes up from his sleep, then he should wash his hands, or say his hands are three before entering them into the vessel, because he does not know where his hand has come from his body, so one doubted that, and he woke up and found his hand had entered his anus and one of his fingers was said .