Sunan an-Nasa'i 1607
سنن النسائي#1607SahihIt was narrated that Abu Hurairah said:The Messenger of Allah (ﷺ) said: 'When any one of you goes to sleep, the Shaitan ties three knots on his head, saying each time: "(Sleep) a long night." If he wakes up and remembers Allah (SWT), one knot is undone. If he performs wudu', another knot is undone. If he prays, all the knots are undone and he starts his day in a good mood and feeling energetic. Otherwise he starts his day in a bad mood and feeling lethargic
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 20:10