Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "When one of you sleeps, Satan ties three knots at the back of his head. With each knot he says: The night is very long, so sleep. When he wakes up and remembers Allah, a knot is untied. If he performs ablution, the second knot is also untied, and if he prays, the third knot is also untied, and the person begins the morning in a happy state. If he does not do this, he begins the morning thoroughly lazy."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4643