Surah Al-Kahf — Ayah 18 (18:18)
وَتَحۡسَبُهُمۡ أَيۡقَاظٗا وَهُمۡ رُقُودٞۚ وَنُقَلِّبُهُمۡ ذَاتَ ٱلۡيَمِينِ وَذَاتَ ٱلشِّمَالِۖ وَكَلۡبُهُم بَٰسِطٞ ذِرَاعَيۡهِ بِٱلۡوَصِيدِۚ لَوِ ٱطَّلَعۡتَ عَلَيۡهِمۡ لَوَلَّيۡتَ مِنۡهُمۡ فِرَارٗا وَلَمُلِئۡتَ مِنۡهُمۡ رُعۡبٗا ١٨
English translation (Saheeh International)
And you would think them awake, while they were asleep. And We turned them to the right and to the left, while their dog stretched his forelegs at the entrance. If you had looked at them, you would have turned from them in flight and been filled by them with terror.
Brief commentary
You - O one who looks at them - will think they are awake, because their eyes are open, though in actual fact they are asleep. I turn them over in their sleep, sometimes to the right and sometimes to the left, so that the earth does not consume their bodies. Their dog that accompanied them stretches out its forelegs at the entrance of the cave. If you had come across them and seen them, you would have turned and run away being afraid of them, and your soul would have been filled with fear of them.