Bulugh al-Maram
Book 9, Hadith 16
Arabic hadith text
وَعَنْ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا قَالَ: قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ مَنْ بَدَّلَ دِينَهُ فَاقْتُلُوهُ } رَوَاهُ اَلْبُخَارِيُّ
Translation
’Abdur Rahman bin Al-Bailamani narrated that The Messenger of Allah (ﷺ) killed a Muslim who killed a Mu'ahid who had made a covenant with the Muslims, and said, “I am closest to the ones who keep their covenants of protection.” Related by 'Abdur Razzaq.