4:82 Will they not then, try to understand this Qur’an? If it were from other than God they would have found in it much contradiction.
Rule is simple “Divine given message is free of contradiction “. Qur’an explains that people have tendency to present their writings with the claim that “This is from Allah “and in this case above rule is a guiding principle as manmade writings can never be free of contradiction .
2:79 Then, lost are those (their scholars) who write the scripture with their own hands and then claim, “This is from God.” They traffic it for petty gains. And loss is to them for what they write, and for the illicit profits they make thereby.”
[In the name of religion, they exploit the masses, feeling unduly proud as they peddle the false notion of them being "the chosen ones". Furthermore, they extort money from the ignorant]