Snoring

إِذَا اسْتَيْقَظَ أُرَاهُ أَحَدُكُمْ مِنْ مَنَامِهِ فَتَوَضَّأَ فَلْيَسْتَنْثِرْ ثَلاَثًا فَإِنَّ الشَّيْطَانَ يَبِيتُ عَلَى خَيْشُومِهِ

"If anyone of you rouses from sleep and performs ablution, he should wash his nose by putting water in it and then blowing it out thrice, because Satan has stayed in the upper part of his nose all the night."

References the nasal passage (khayshum) during sleep where airway obstruction contributing to snoring occurs, recommending nasal clearing upon waking.

أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ إِذَا عَرَّسَ بِلَيْلٍ اضْطَجَعَ عَلَى يَمِينِهِ وَإِذَا عَرَّسَ قُبَيْلَ الصُّبْحِ نَصَبَ ذِرَاعَهُ وَوَضَعَ رَأْسَهُ عَلَى كَفِّهِ

"When the Prophet (peace be upon him) lay down at night, he would lie on his right side, and when he lay down just before dawn, he would prop up his forearm and rest his head on his palm."

The right-side sleeping position recommended by the Prophet reduces airway collapse and tongue obstruction that causes snoring, a principle recognized in modern sleep medicine.