Surah Al-Kahf Ayah 86

حَتَّىٰٓ إِذَا بَلَغَ مَغۡرِبَ ٱلشَّمۡسِ وَجَدَهَا تَغۡرُبُ فِي عَيۡنٍ حَمِئَةٖ وَوَجَدَ عِندَهَا قَوۡمٗاۖ قُلۡنَا يَٰذَا ٱلۡقَرۡنَيۡنِ إِمَّآ أَن تُعَذِّبَ وَإِمَّآ أَن تَتَّخِذَ فِيهِمۡ حُسۡنٗا ٨٦

Ḥattā idhā balagha maghribash-shamsi wajadahā taghrubu fī ʿaynin ḥamiʾatiw wa wajada ʿindahā qawmā, qulnā yādhal-qarnayni immā an tuʿadhdhiba wa immā an tattakhidha fīhim ḥusnā.

Until, when he reached the setting of the sun [i.e., the west], he found it [as if] setting in a body of dark water,¹ and he found near it a people. We [i.e., Allāh] said, "O Dhul-Qarnayn, either you punish [them] or else adopt among them [a way of] goodness."

Translation: Sahih International