Surah Al-Kahf, Verse 11

فَضَرَبۡنَا عَلَىٰٓ ءَاذَانِهِمۡ فِي ٱلۡكَهۡفِ سِنِينَ عَدَدٗا١١

faḍarabnā ʿalā ādhānihim fī l-kahfi sinīna ʿadadan

So We cast [a cover of sleep] over their ears within the cave for a number of years.