Shayṭān sleeps in your nose overnight

[IqbalAli]

The importance of performing Wuḍūʾ before morning Salāt

Hadith 4:516

Narrated Abu Huraira: The Prophet said, “If anyone of you rouses from sleep and performs the ablution, he should wash his nose by putting water in it and then blowing it out thrice, because Shayṭān has stayed in the upper part of his nose all the night.”