Volume 2, Book 21, Number 243:
Narrated Abu Huraira:
Allah’s Apostle said, “Satan puts three knots at the back of the head of any of you if he is asleep. On
every knot he reads and exhales the following words, ‘The night is long, so stay asleep.’ When one
wakes up and remembers Allah, one knot is undone; and when one performs ablution, the second
knot is undone, and when one prays the third knot is undone and one gets up energetic with a good
heart in the morning; otherwise one gets up lazy and with a mischievous heart.”