Knowledge of Arabic is not sufficient for understanding the Qur’aan
From what has been stated previously, it becomes clear that there is no way for anyone, even if he be a scholar of the Arabic Language and its disciplines, to understand the noble Qur’aan, without seeking assistance in that from the Prophet’s Sunnah in speech and action. This is since he will never be more knowledgeable of the language than the Companions of the Prophet, those who the Qur’aan was revealed to in their language. And (at that time) the language was not blemished with the errors of the non-Arabs and the slang of the common people, but in spite of that, they still erred in understanding these previously mentioned ayaat, when they relied on their knowledge of the language only.