A man came to the Prophet (PBUH) and said: So-and-so fell asleep yesterday and missed the prayer. The Messenger of Allah (PBUH) said: That is a man in whose ear (or in whose ears) the devil urinated.

When one of you goes to sleep, Satan ties three knots on the back of his neck, sealing every knot with: You have a long night, so sleep. If he wakes up and remembers Allah, one knot will be untied. If he performs ablution, another knot will be untied. If he prays, last knot will be untied and he becomes energetic and in good spirits. Otherwise, he becomes in low spirits and sluggish.