In Surah Al-Kahf Ayah (18:86) it says that the setting place of the Sun is in a muddy spring. Does this go against modern scientific knowledge? It is well known that the Sun does not set in a muddy spring. Many people claim that unlike the Bible and Torah, the Qur’an is free of scientific mistakes. I am aware that the Qur’an has many miracles but please explain to me this verse of the Qur’an.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Some of the enemies of Islam claim that the Qur'an contains mistakes or is contradicting reality, etc.  The truth is otherwise.

The Qur'an was revealed by The Most-Wise, the All-Knower Who has created this universe.

There is nothing that takes place except that Allah is aware about it. Should not He Who has created know?  And He is the Most Kind and Courteous to His slaves, All-Aware of everything.

As regards the subject of the question, the Ayah (verse) is from the story of the just king Dhul-Qarnain.   The interpretation of “the sun setting in a spring of black muddy water”, in the books of Tafseer is the following: Dhul-Qarnain went towards the direction of the West until he reached the farthest place in the West.  There he found as if the sun was setting in a black muddy water. If a person among ourselves stands at the shore (sea-side) at sun set, he will see the sun as if it is falling into the sea, or setting into the sea.

But the reality is otherwise, when the sun sets in one place, it is still rising on another place

Therefore, what is meant by the verse “he found the sun setting in a muddy water” means when someone looks at it, that is what he/she would think and see.

Perhaps, Dhul-Qarnain arrived to a place where a river in deluge meets with the sea.  The water of the river may contain mud, and when the sun sets, it would appear to a person looking at it as if it sets in a muddy water.

For more information about this subject you can refer to Tafseer books (books about the interpretation of the meaning of the Holy Qur'an).

Allah knows best.