Until when he reached the place where the sun set, he found it going down into a black sea, and found by it a people. We said: O Zulqarnain! either give them a chastisement or do them a benefit.

And if We make him taste mercy from Us after distress that has touched him, he would most certainly say: This is of me, and I do not think the hour will come to pass, and if I am sent back to my Lord, I shall have with Him sure good; but We will most certainly inform those who disbelieved of what they did, and We will most certainly make them taste of hard chastisement.

Say to those of the dwellers of the desert who were left behind: You shall soon be invited (to fight) against a people possessing mighty prowess; you will fight against them until they submit; then if you obey, Allah will grant you a good reward; and if you turn back as you turned back before, He will punish you with a painful punishment.