Quran's miraculous nature

وَلَقَدْ نَعْلَمُ أَنَّهُمْ يَقُولُونَ إِنَّمَا يُعَلِّمُهُۥ بَشَرٌ ۗ لِّسَانُ ٱلَّذِى يُلْحِدُونَ إِلَيْهِ أَعْجَمِىٌّ وَهَـٰذَا لِسَانٌ عَرَبِىٌّ مُّبِينٌ

And We certainly know that they say, "It is only a human being who teaches him [i.e., the Prophet (ﷺ)]." The tongue of the one they refer to is foreign, and this [recitation, i.e., Qur’ān] is [in] a clear Arabic language.

يَهْدِىٓ إِلَى ٱلرُّشْدِ فَـَٔامَنَّا بِهِۦ ۖ وَلَن نُّشْرِكَ بِرَبِّنَآ أَحَدًا

It guides to the right course, and we have believed in it. And we will never associate with our Lord anyone.