18:11
فَضَرَبْنَا عَلَىٰٓ ءَاذَانِهِمْ فِى ٱلْكَهْفِ سِنِينَ عَدَدًۭا ١١
Saheeh International
So We cast [a cover of sleep] over their ears within the cave for a number of years.
Tafsir of "Ibn Kathir" (English)
Therefore, We covered up their hearing in the cave for a number of years.meaning, `We caused them to sleep when they entered the cave, and they slept for many years.