Qul innamaaa a'izukum biwaahidatin an taqoomoo lillaahi masnaa wa furaadaa summa tatafakkaroo; maa bisaahibikum min jinnah; in huwa illaa nazeerul lakum baina yadai 'azaabin shadeed
Say, "I only advise you of one [thing] - that you stand for Allah, [seeking truth] in pairs and individually, and then give thought." There is not in your companion any madness. He is only a warner to you before a severe punishment.