Quran 18:11

فَضَرَبْنَا عَلَىٰٓ ءَاذَانِهِمْ فِى ٱلْكَهْفِ سِنِينَ عَدَدًۭا

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

Translation · Saheeh International