وَلَقَدْ نَعْلَمُ أَنَّهُمْ يَقُولُونَ إِنَّمَا يُعَلِّمُهُ بَشَرٌ ۗ لِسَانُ الَّذِي يُلْحِدُونَ إِلَيْهِ أَعْجَمِيٌّ وَهَٰذَا لِسَانٌ عَرَبِيٌّ مُبِينٌ

Surah An-Nahl : 103
And We certainly know that they say, "It is only a human being who teaches the Prophet." The tongue of the one they refer to is foreign, and this Qur'an is [in] a clear Arabic language.

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