Read and reflect on verse 648 from Surah An-Nisaa: And so, [We punished them] for the breaking of their pledge, and their refusal to acknowledge God's messages, and their slaying of prophets against a...
فَبِمَا نَقْضِهِمْ مِيثَاقَهُمْ وَكُفْرِهِمْ بِآيَاتِ اللَّهِ وَقَتْلِهِمُ الْأَنْبِيَاءَ بِغَيْرِ حَقٍّ وَقَوْلِهِمْ قُلُوبُنَا غُلْفٌ ۚ بَلْ طَبَعَ اللَّهُ عَلَيْهَا بِكُفْرِهِمْ فَلَا يُؤْمِنُونَ إِلَّا قَلِيلًا
And so, [We punished them] for the breaking of their pledge, and their refusal to acknowledge God's messages, and their slaying of prophets against all right, and their boast, "Our hearts are already full of knowledge"- nay, but God has sealed their hearts in result of their denial of the truth, and [now] they believe in but few things -;