Muwatta Imam Malik (Riwayat Ibn al-Qasim)

And with this chain (it is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him) that the Messenger of Allah, peace and blessings be upon him, said: "When you sleep, Satan ties three knots at the back of your neck. On each knot he says, 'The night is long, so sleep.' Then when he wakes up and remembers Allah, one knot is untied. Then when he performs ablution, the second knot is untied. Then when he prays, the third knot is untied, and the person enters the morning energetic and in a good mood. And if he does not do so, he enters the morning sluggish, tired, and in a bad mood."