Amatul Rahmân Omer:
So that when he reached (the land of) the setting of the sun, (the western most part of his empire,) he found it (- the sun) disappearing (as if) in a vast muddy pool of murky water (- the Black Sea), and close to it he found a certain people. We said, `Dhul-Qarnain! you may either punish (them) or treat them with kindness. (They being at your disposal.)´
