Riyad us Saliheen: Hadith 1164

The Messenger of Allah (ﷺ) said, "When any one of you sleeps, Satan ties three knots at the back of his neck. He recites this incantation at every knot: 'You have a long night, so sleep.' If he awakes and remembers Allah, one knot is loosened. If he performs Wudu', the (second) knot is loosened; and if he performs prayer, (all) knots are loosened. He begins his morning in a happy and refreshed mood; otherwise, he gets up in bad spirits and sluggish state."

[Al-Bukhari and Muslim].