Al-Isra' - 17:88

قُل لَّئِنِ اجْتَمَعَتِ الإِنسُ وَالْجِنُّ عَلَى أَن يَأْتُواْ بِمِثْلِ هَـذَا الْقُرْآنِ لاَ يَأْتُونَ بِمِثْلِهِ وَلَوْ كَانَ بَعْضُهُمْ لِبَعْضٍ ظَهِيرًا
[17:88]
Say: If men and jinn should combine together to bring the like of this Quran, they could not bring the like of it, though some of them were aiders of others.
Say: "If the whole of mankind and Jinns were to gather together to produce the like of this Qur'an, they could not produce the like thereof, even if they backed up each other with help and support.
Say: Verily, though mankind and the jinn should assemble to produce the like of this Qur'an, they could not produce the like thereof though they were helpers one of another.