Verse 17

وَتَرَى ٱلشَّمْسَ إِذَا طَلَعَت تَّزَٰوَرُ عَن كَهْفِهِمْ ذَاتَ ٱلْيَمِينِ وَإِذَا غَرَبَت تَّقْرِضُهُمْ ذَاتَ ٱلشِّمَالِ وَهُمْ فِى فَجْوَةٍ مِّنْهُ ذَٰلِكَ مِنْ ءَايَـٰتِ ٱللَّهِ مَن يَهْدِ ٱللَّهُ فَهُوَ ٱلْمُهْتَدِ وَمَن يُضْلِلْ فَلَن تَجِدَ لَهُۥ وَلِيًّا مُّرْشِدًا

And you would see the sun rose to the right side of the cave and set to the left side, as they were inside its cavity. These are from God’s signs. And whomever God guides then is truly guided, and whoever goes astray, then you will never find a guiding protector for him.