وَلَقَدۡ نَعۡلَمُ اَنَّهُمۡ يَقُوۡلُوۡنَ اِنَّمَا يُعَلِّمُهٗ بَشَرٌؕ لِسَانُ الَّذِيۡ يُلۡحِدُوۡنَ اِلَيۡهِ اَعۡجَمِيٌّ وَّهٰذَا لِسَانٌ عَرَبِيٌّ مُّبِيۡنٌ

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