Question: The Holy Qur’an in Surah Kahf states with reference to the legend of Zulqarnain:
When he reached the place where the sun set, he found it going down into a black sea,(18:86)
What is meant by this dark water? How this is possible that even though the sun being with all its greatness can go down in the dark waters? And is not this against the fact earth is spherical and rotates round the sun; and against the new assertions of the celestial sciences.
Answer: According to those latest research that the Islamic scholars and highly respected writers of Qur’anic exegesis have done with respect to the legend of Zulqarnain the meaning of above-mentioned verse is this:
Zulqarnain continued his attack forward in the direction of the West in the same way till he reached to the shore of two oceans.
In this regard there is a difference between the Mufassereen (commentators) that, by oceans is it meant to be the sea of Uqiyanus or it is the Mediterranean and whether the attack by Zulqarnain was to the west to its last limit upto the area of Marakish or up to Azmeer in Turkey.
In any ease it was the time of sunset when Zulqarnain was standing on the shore and looking at the astonishing sight, because when a person stands on the seashore, then due to the earth being spherical, at the time of sunset he gets to see that the sun is slowly going down in the sea on the last point of the horizon. On the same basis the Holy Qur’an also narrates the state and the feelings of Zulqarnain in this way.
“He felt that as if the sun is drowning in the dark water.”
Thus the verse is completely in concordance regarding the earth's spherical shape and by “ain-e-hamaa” is meant to be the same ocean in the last point of whose horizon the sun had set.
Nevertheless it is a separate question that why the Holy Qur’an has interpreted the water of the ocean as “aineen”?
Mufassereen have explained it in this way:
The word “aine” has seven meanings and one of them is “more water” and another is “the place where water falls.” Since the water is more in seas and oceans and rivers, canals, streams and big seas generally fall into this and the water of the seas also adjoin with the water of the oceans. Therefore the Holy Qur’an has interpreted it with his word “aine” as plenty of water and delta of water.
As far as the question that why the Holy Qur’an has interpreted this seawater as dark water is concerned some reasons can be given to that:
(1) The river water containing soil, which falls into the sea and the soil on the shore and under the influence of sediment, the water of the seashore becomes muddy, and that takes the color of dust.
(2) In fact when at the time of sunset its rays fall on seawater, it takes up a dark color. This is the reason that the Holy Qur’an has compared it with muddy water.
(3) Water which is more and deeper, under the effect of intensity of blue color, looks black since Zulqarnain saw that sea-water which was much more and it had acquired the state which was almost blackish, that is why the Holy Qur’an has interpreted it as the water mixed with black soil.1