وَإِن نَّكَثُوٓا۟ أَيْمَـٰنَهُم مِّنۢ بَعْدِ عَهْدِهِمْ وَطَعَنُوا۟ فِى دِينِكُمْ فَقَـٰتِلُوٓا۟ أَئِمَّةَ ٱلْكُفْرِ ۙ إِنَّهُمْ لَآ أَيْمَـٰنَ لَهُمْ لَعَلَّهُمْ يَنتَهُونَ

And if they break their oaths after their treaty and defame your religion, then fight the leaders of disbelief, for indeed, there are no oaths [sacred] to them; [fight them that] they might cease.

— At-Taubah 9:12