This is actually an apologist lie. The Qur’an uses the word “wajada,” which means “he found” and is best translated as “he found.” The qur’an could have easily said “ra’aaha ka’annahaa taghrubu fi ainin…,” or “he saw it as if it were setting in a fetid spring.” Instead, it says “wajadahaa taghrubu fi ainin hami’atin…,” or “He found it setting in a fetid spring.”
Now, the apologists love to say that the word “wajada” or “he found” implies Thul Qarnain’s perception and not the reality, but that is absolute nonsense. The same word is used in the same surah for other things that travelers found. For example, “wa wajada ‘indaha qawma” or “he found there at a people.” Does that mean that they only appeared to be people? Were they really monkeys or grizzly bears?
Also, in the story of Musa and khidr in the same surah, it says “wajadaa fihaa jidaaran yureedu an yanqadha..” “They found therein a wall which was about to collapse.” Did it only appear to be a wall? Was it really just a hanging bed sheet?
It is so silly the things they will say.
And what of the other defence, that apparently he reached a place at the
time of sunset or something like that?