Testing and awakening people's conscience

فَجَعَلَهُمْ جُذَٰذًا إِلَّا كَبِيرًا لَّهُمْ لَعَلَّهُمْ إِلَيْهِ يَرْجِعُونَ

So he made them into fragments, except a large one among them, that they might return to it [and question].