And they ask you, [O Muhammad], about Dhul-Qarnayn. Say, "I will recite to you about him a report."

Indeed We established him upon the earth, and We gave him to everything a way.

So he followed a way

Until, when he reached the setting of the sun, he found it [as if] setting in a spring of dark mud, and he found near it a people. Allah said, "O Dhul-Qarnayn, either you punish [them] or else adopt among them [a way of] goodness."