(Al-Hajj) 22 : 53
لِيَجْعَلَ مَا يُلْقِي الشَّيْطَانُ فِتْنَةً لِلَّذِينَ فِي قُلُوبِهِمْ مَرَضٌ وَالْقَاسِيَةِ قُلُوبُهُمْ ۗ وَإِنَّ الظَّالِمِينَ لَفِي شِقَاقٍ بَعِيدٍ
It is so to make what Satan throws in as a trial for those who have a disease in their hearts and those hardened their heart; and indeed, the wrongdoers are in schism.
Those who have hardened their hearts are the hypocrites who hide Adhikr; and those having a disease in their hearts are the Kuffar. So Lord has promised Hellfire for these Fujjar as explained in verses 9: 67-68. Both of these worst creatures will be killed by the other people belonging to Messenger’s community as explained in verses 9: 5 and 123. See explanation 2: 176; 3: 90-91 and 10: 88.