Al A’raf Ayah 184

أَوَلَمْ يَتَفَكَّرُواْ‌ۗ مَا بِصَاحِبِهِم مِّن جِنَّةٍ‌ۚ إِنْ هُوَ إِلَّا نَذِيرٌ مُّبِينٌ ١٨٤ Have they not ever given it a thought? Their fellow man is not insane. He is only sent with a clear warning.