They ask you about Dhu'l-Qarnain. 83 We had given him great power in the land and all kinds of resources. 84 He journeyed on a way 85 until when he reached the very limits where the sun sets, he saw it setting in dark turbid waters; and nearby he met a people. We said: "O Dhu al-Qarnayn, you have the power to punish or to treat them with kindness." 86 He said: as for him who doeth wrong, presently we shall torment him, and thereafter he shall be brought back to his Lord, and He shall torment him with a torment formidable. 87 But as for him who believes and acts righteously, his will be a goodly reward and we shall enjoin upon him only mild commands." 88 He again pursued a purpose. 89 until he reached the rising of the sun, he found it rising upon a nation for whom We provided no veil against it to shade them. 90 thus [We had made them, and thus he left them; and We did encompass with Our knowledge all that he had in mind 91 Then he followed (another) way, 92 until he came between two mountains. He found beside them a people who could scarcely understand a word [of his language]. 93 'ThulKarnain' they said, 'Look, Gog and Magog are corrupting the earth. Build for us a barrier between us and them, and we will pay you a tribute' 94 He answered: "Whatever my Lord has granted me is good enough. But help me with your labour and I will erect a rampart between you and them. 95 Bring me sheets of iron" - until, when he had leveled [them] between the two mountain walls, he said, "Blow [with bellows]," until when he had made it [like] fire, he said, "Bring me, that I may pour over it molten copper." 96 (Thus he constructed the barrier which) neither Gog nor Magog were able to climb nor were they able to dig a tunnel through the iron and brass barrier. 97 He said: This is a mercy from my Lord; but when the promise of my Lord cometh to pass, He will lay it low, for the promise of my Lord is true. 98 ۞ And on that day We will leave a part of them in conflict with another part, and the trumpet will be blown, so We will gather them all together; 99 And on that Day We shall place hell, for all to see, before those who denied the truth 100 whose eyes had become blind against My admonition and who were utterly disinclined to hear it. 101