Why the Quran is
Not from Allah:
10 Reasons
#9
According to the sahih (authentic) hadith, Muhammad believed that the sun set each day in a spring of water. As the creator, God would know the truth.
So... whose version made it into the Quran? Muhammad's, of course! (see verse 18:86) He was the one who wrote the Quran - not God.
Quran 18: 86, which means:
(86. [And Alexander of Macedon went westward b in his march]
until when he reached at sun-set [time];
he found the [sun] setting under the observation of a black woman, and he found with her a people c;d
We said: "O 'Zul-qarnain'e, you have either to punish [these people who worship the sun if they do not believe], or to show them kindness [if they believe.]")
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86 b Of Macedonia, his country.
Alexander set from Macedonia to conquer Turkey then to Egypt where he built Alexandria city. Then he continued his march to Sudan, [and he reached to a region in Sudan at the sun-set time.]
86 c The black woman was their queen.
The meaning: He found the sun set on a people watching the sun at its sunset time, and they prostrated themselves to it. They had a black queen leading them in prayer.
That is because when Alexander reached to Sudan, he found the citizens of that country worship the sun; so they gathered on the day of their festival outside the city at the sunset time, watched the sun, and hymned their religious hymns; then when it was about to hide from sight [behind the horizon], then all of them would prostrate themselves to it.
So the Arabic word in the aya here means the ‘observation and watching’, [not the ‘water spring’.]
86 d It means: Alexander found with the black woman a people who acted like her act and imitated her in her prostration to the sun.
86 e Which is the surname of Alexander.
http://quran-ayat.com/pret/18.htm#a18_86
quran-ayat.com/pret/18.htm#a18_86