Why do they not reflect upon their friend (the messenger)? He is not crazy. He is simply a profound warner.
أَوَلَم يَتَفَكَّروا ما بِصاحِبِهِم مِن جِنَّةٍ إِن هُوَ إِلّا نَذيرٌ مُبينٌ
awalam yatafakkaroo maa bisaahibihim min jinnah; in huwa illaa nazeerun mubeen