It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Satan ties three knots at the back of the head of any one of you while he is sleeping. On each knot he says, "The night is long, so sleep." If the person wakes up and remembers Allah, one knot is undone. If he performs ablution, two knots are undone. And if he offers prayer, all the knots are undone, and he starts his morning in a state that his heart is content and he is energetic. Otherwise, he enters the morning with a dirty heart and is lazy, and he attains no good.