21وَما كانَ لَهُ عَلَيهِم مِن سُلطانٍ إِلّا لِنَعلَمَ مَن يُؤمِنُ بِالآخِرَةِ مِمَّن هُوَ مِنها في شَكٍّ ۗ وَرَبُّكَ عَلىٰ كُلِّ شَيءٍ حَفيظٌ(Irfan-ul-Quran)And Satan had no power over them but for the reason that We might distinguish those who believe in the Hereafter from those who are in doubt about it. And your Lord is Watchful over everything.