Verses 18:84-86

إِنَّا مَكَّنَّا لَهُۥ فِى ٱلْأَرْضِ وَءَاتَيْنَـٰهُ مِن كُلِّ شَىْءٍ سَبَبًا

فَأَتْبَعَ سَبَبًا

حَتَّىٰٓ إِذَا بَلَغَ مَغْرِبَ ٱلشَّمْسِ وَجَدَهَا تَغْرُبُ فِى عَيْنٍ حَمِئَةٍ وَوَجَدَ عِندَهَا قَوْمًا ۗ قُلْنَا يَـٰذَا ٱلْقَرْنَيْنِ إِمَّآ أَن تُعَذِّبَ وَإِمَّآ أَن تَتَّخِذَ فِيهِمْ حُسْنًا

“Indeed We established him in the land, and gave him a means to everything. So he followed a course, until, when he reached the setting of the sun, he found it setting in a muddy spring, and found near it a people. We said: O Dhū al-Qarnayn, either you punish them, or you adopt a good way with them.”