Hazrat Amr bin Shu'aib narrates from his father, who narrates from his grandfather, that the Holy Prophet (peace and blessings be upon him) said on the day of the conquest of Makkah: Except for Khuza'ah, restrain (the rest of) Banu Bakr from weapons. And the Prophet (peace and blessings be upon him) gave permission to Khuza'ah until they had performed the Asr prayer, then the Prophet (peace and blessings be upon him) ordered them: You (also) restrain from weapons. After this, the next day, a man from Banu Khuza'ah met a man from Banu Bakr and killed the man from Banu Bakr at Muzdalifah. This news reached the Messenger of Allah (peace and blessings be upon him), so he stood up to deliver a sermon and said: The person who is the most hostile to Allah among the people is the one who kills (someone) in the Haram, and (the one) who kills anyone other than his killer, and (the one) who kills in revenge from the days of ignorance.