Additionally, they are contradicting the Messenger (peace be upon him) who said that the best speech is the Qur'an. Describing the Glorious Qur'an, Allah (may He be Praised) says, A revelation from (Allâh), the Most Gracious, the Most Merciful. and: And truly, this (the Qur'ân) is a revelation from the Lord of the 'Alamîn (mankind, jinn and all that exists), Which the trustworthy Rûh [Jibrîl (Gabriel)] has brought down He also says, And this (the Qur'ân) is a blessed Book which We have sent down and: Verily, We, it is We Who have sent down the Dhikr (i.e. the Qur'ân) and surely, We will guard it (from corruption). He says, it is an honourable wellfortified respected Book (because it is Allâh's Speech, and He has protected it from corruption). Falsehood cannot come to it from before it or behind it: (it is) sent down by the AllWise, Worthy of all praise (Allâh ﻋﺰ ﻭﺟﻞ).
There are many other Ayahs in the Qur'an that affirm this meaning.
Anyone who claims that this Book contains contradictions and some myths received by the Messenger (peace be upon him) from the desert, is claiming that some parts of the Qur'an are neither sent down by Allah nor divinely guarded. By making such a claim they have described the Messenger of Allah (peace be upon him) as a liar who fabricated lies against Allah and inserted into His Book words that are not part of it, but in spite of this they state before people that the Qur'an is the Word of Allah. That is the worst calumny against the Messenger of Allah (peace be upon him), describing him as lying against Allah and deceiving people, which is among the most abominable acts of Kufr (disbelief), perversity and injustice.
Allah (may He be Praised) says, Then, who does more wrong than one who utters a lie against Allâh, and denies the truth [this Qur'ân, the Prophet (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭ ﺳﻠﻢ) and the Islâmic Monotheism] when it comes to him! Is there not in Hell an abode for the disbelievers? and: And who can be more unjust than he who invents a lie against Allâh, or says: "A revelation has come to me", whereas no revelation has come to him in anything He (Exalted be He) also says, Say: "Was it at Allâh (ﻋﺰ ﻭﺟـﻞ), and His Ayât (proofs, evidence, verses, lessons, signs, revelations) and His Messenger ( ﺻـﻠﻰ ﺍﷲ ﻋﻠﻴـﻪ ﻭﺳـﻠﻢ) that you were mocking?" Make no excuse; you disbelieved after you had believed.
Scholars of Tafsir stated that this Ayah was revealed concerning a group of people who accompanied the Prophet (peace be upon him) in the Battle of Tabuk. Some of them said, "We have never seen people who love their stomachs more nor tell more lies nor are more cowardly in battle than these Qur'anreaders". Others said, "Do you think that fighting Banu Al Asfar (i.e. Byzantines) is like the fighting of Arabs. By Allah! You, tomorrow, will be tied with ropes". Some of them added, "He (i.e. the Prophet) thinks that he is able to conquer the palaces and castles of the Byzantines. How impossible!" So Allah (may He be Praised) revealed the following Ayah, If you ask them (about this), they declare: "We were only talking idly and joking." Say: "Was it at Allâh (ﻋﺰ ﻭﺟﻞ), and His Ayât (proofs, evidence, verses, lessons, signs, revelations) and His Messenger (ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) that you were mocking?" Make no excuse; you disbelieved after you had believed.
They came to the Prophet (peace be upon him) to beg his pardon saying that they were only talking idly, joking and speaking like the people in a traveling caravan not to get bored of the road! The Messenger of Allah (peace be upon him) did not forgive them, saying, "Was it at Allâh (ﻋﺰ ﻭﺟﻞ), and His Ayât (proofs, evidence, verses, lessons, signs, revelations) and His Messenger (ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) that you were mocking?" Make no excuse; you disbelieved after you had believed.
If their speech was considered mockery of Allah, His Ayahs and His Messenger and as declaration of Kufr after professing Iman (Faith), the case of the persons who claim contradictions and myths in the Qur'an or claim that the Prophet (peace be upon him) is naïve and cannot distinguish between the truth and superstitions is undoubtedly a far worse mockery and a much graver act of Kufr.