Al-Mughira said that the Prophet got up at night to such an extent that his feet became swollen. On being asked why he did this when his former and latter sins had been forgiven him, he replied, “Should I not be a grateful servant?”
Abu Huraira reported God’s Messenger as saying, “When 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 God a knot will be loosened, if he performs ablution a knot will be loosened, and if he prays a knot will be loosened, and in the morning he will be active and in good spirits; otherwise he will be in bad spirits and sluggish in the morning.”
Ibn Mas'ud said that a man was mentioned in the Prophet’s presence, and he was told that he continued sleeping till morning, never having got up to pray. He said, “That is a man in whose ear (or, in whose ears) the devil has urinated.”
Rabi'a b. Ka‘b al-Aslami said he used to spend the night near the Prophet’s inner chamber and hear him say when he got up during the night, “Glory be to the Lord of the universe" for a long time. Then he would say, “Glory be to God and praise be to Him" for a longtime.
Nasa’i transmitted it, and Tirmidhi who has something similar says that this is a hasan sahih tradition.
