9-Surah At-Taubah ( The Repentance ) 12
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.
وَإِن نَّكَثُوا أَيْمَانَهُم مِّن بَعْدِ عَهْدِهِمْ وَطَعَنُوا فِي دِينِكُمْ فَقَاتِلُوا أَئِمَّةَ الْكُفْرِ ۙ إِنَّهُمْ لَا أَيْمَانَ لَهُمْ لَعَلَّهُمْ يَنتَهُونَ
Quran's Tafhim ( explanation)
*15) In the context,the words, oaths and compacts mean the compact of the acceptance of Islam. Therefore, the question of making a new compact with them does not arise. As regards the old pacts, they had already broken all of them. It is on account of this that the declaration of immunity (from obligations) by Allah and His Messenger has been clearly made. It has also been stated that such people are not worthy of any treaty and they can only be let off if they repent of their disbelief and shirk and establish Salat and pay Zakat dues. This verse states clearly how the renegades should be treated. As a matter of fact, .this verse forestalled the mischief of apostasy that broke out a year and a half after its revelation and Hadrat Abu Bakr followed the guidance given in this verse to crush it. (For further explanation, see my book entitled Murtad ki Saza Islami Qanun men).