Shaytaan`s tying of knots at night

Narrated by Abu Hurairah (RA): Allah`s Messenger (SAW) said: "During your sleep, Shaytaan knots 3 knots at the back of the head of each one of you. On every knot he reads and exhales the following words - 'The night is long for you to stay asleep.' When that person wakes up and remembers Allah, one knot is undone; and when he performs ablution, the second knot is undone; and when he offers Salah (prayer), the third knot is undone and he gets up energetic in a good mood and with a good heart in the morning; otherwise he gets up in a bad mood, lazy (and with not a good heart). [Sahih Bukhari, Book of Prayer 19, Chpt 10, No. 604]