'Abdullah (b. Mas'ud) reported that a mention was made of a man who slept the whole night till morning. He (the Holy Prophet) remarked: That is a man in whose ears (or in whose ear) the devil urinated.

Husain bin 'Ali narrated on the authority of (his father) 'Ali bin Abu Talib that the Apostle of Allah ( صلی اللہ علیہ وسلم ) came one night to see him ('Ali) and Fatimah (the daughter of the Holy Prophet) and said: Don't you observe (Tahajjud) prayer? I ('Ali) said: Messenger of Allah, verily our souls are in the hands of Allah and when He wants to awaken us, He awakens us. The Messenger of Allah ( صلی اللہ علیہ وسلم ) went back when I said this to him. He was striking his hand on his thigh while returning, and I heard him say: Verily the man disputes with many things.

Abu Hurairah (RA) transmitted it from the Apostle of Allah ( صلی اللہ علیہ وسلم ): When any one of you goes to sleep, the devil ties three knots at the back of his neck, sealing every knot with:" You have a long night, so sleep." So if one awakes and mentions Allah, a knot will be loosened; if he performs ablution two knots are loosened; and if he prays (all) knots will be loosened, and in the morning he will be active and in good spirits; otherwise we will be in bad spirits and sluggish in the morning.