Overall meaning : The Almighty says: The unbelievers ask you, Muhammad, about Dhul-Qarnayn. Say to them, ‘I will give you an account of him, in which there will be a lesson for you.’ We gave him power and authority on earth and granted him all kinds of ways and means to accomplish all his ends. He journeyed on a certain road, using the means at his disposal, until he reached the furthest place he could on the western part of the earth. There he found the sun as if setting—from his perspective—in a spring of black mud; and nearby he found a certain people. ‘Dhul-Qarnayn,’ We said to him, ‘you can either punish those among them who persist in their unbelief or treat them with gentleness and thus show them the right path.’
He said, ‘We will punish those among them who stubbornly persist in their unbelief, then they will be returned to their Lord, who will inflict on them a terrible punishment. As for those among them who believe in their Lord and do good deeds, they will receive an excellent reward from Allah—Paradise. On our part, we will deal indulgently with them and assign to them a task that is easy to fulfil.’
Dhul-Qarnayn then journeyed eastwards, using the ways and means Allah had given him, until he reached the furthest place he could on the eastern part of the earth. There he found the sun rising on a people to whom We had not given any shelter from it. Thus it was; and We had full knowledge of him and of all the forces at his command.