Fussilat 41:44

وَلَوۡ جَعَلۡنَٰهُ قُرۡءَانًا أَعۡجَمِيّٗا لَّقَالُواْ لَوۡلَا فُصِّلَتۡ ءَايَٰتُهُۥٓۖ ءَا۬عۡجَمِيّٞ وَعَرَبِيّٞۗ قُلۡ هُوَ لِلَّذِينَ ءَامَنُواْ هُدٗى وَشِفَآءٞۚ وَٱلَّذِينَ لَا يُؤۡمِنُونَ فِيٓ ءَاذَانِهِمۡ وَقۡرٞ وَهُوَ عَلَيۡهِمۡ عَمًىۚ أُوْلَـٰٓئِكَ يُنَادَوۡنَ مِن مَّكَانِۭ بَعِيدٖ 44

And if We had made it a non-Arabic Qur'an, they would have said, "Why are its verses not explained in detail [in our language]? Is it a foreign [recitation] and an Arab [messenger]?" Say, "It is, for those who believe, a guidance and cure." And those who do not believe - in their ears is deafness, and it is upon them blindness. Those are being called from a distant place