Errors in the Quran?

Two criticisms come up often:

Criticism 1: The Sun sets in a muddy spring?

Some see a scientific error in this verse:

“Until, when he reached the setting of the sun, he found it setting in a spring of dark mud, and he found near it a people. Allah said: ‘O Dhul-Qarnayn, either you punish [them] or else adopt among them [a way of] goodness.’”— Surah Al-Kahf (18:86)

The Quran does not say that the sun actually sets in a spring.

It says: “he found it” — meaning from Dhul-Qarnayn's point of view.

It is like saying: “The sun rises.” That is a visual perception, not a physical reality.

Criticism 2: Inheritance

Sunnism does not rely solely on the Quran — it also includes the Sunnah and the Ijma.

The Quran gives shares for distributing inheritance (non-exhaustive list):

Wife: 1/8 (if children), otherwise 1/4.
Two daughters or more: 2/3 (if no son).
Father: 1/6 (if children).
Mother: 1/6 (if children or multiple brothers/sisters), otherwise 1/3.

Example

If a man leaves:

Two daughters (receive 2/3).
A father (receives 1/6).
A mother (receives 1/6).

The total is 2/3 + 1/6 + 1/6 = 6/6.

Another example

If a man leaves:

A wife (receives 1/8).
Two daughters (receive 2/3).
A father (receives 1/6).
A mother (receives 1/6).

And if we add these shares: 1/8 + 2/3 + 1/6 + 1/6 = 27/24.

You cannot give 27 slices of a cake that has only 24.

The legal method applied in this situation is called Al-Awl.

It is a proportional reduction. The cake is no longer in /24, it becomes /27. The wife therefore receives 3/27, the daughters 16/27, etc. The total is 100% and the proportion between the shares is respected.

The criticism claims that this method is a problem, since it is not mentioned in the Quran.

But it was the Prophet ﷺ himself who designated Zayd as the authority on inheritance matters.

“The most knowledgeable of my nation in matters of inheritance is Zayd bin Thabit.”

And when this case (27/24) arose, the Companions unanimously agreed (Ijma) to apply Al-Awl.

The criticism only makes sense if one rejects the Sunnah and the Ijma.

But rejecting them is not a criticism of Sunnism, but rather of the Quranist methodology .