It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he (peace and blessings be upon him) said: "When any of you wakes up from sleep, let him perform ablution and blow his nose three times, for Satan spends the night on the bridge of his nose."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 226