It is narrated from Sayyiduna Abu Shurayh bin Amr al-Khuza'i (may Allah be pleased with him), who was one of the Companions of the Messenger of Allah (peace and blessings be upon him), that on the day of the Conquest of Makkah, Banu Ka'b met a man from Hudhayl from whom they were seeking some vengeance from the time of Jahiliyyah. He was in the Sanctuary, heading toward the Messenger of Allah (peace and blessings be upon him) to pledge allegiance to him on Islam, and they killed him. When this reached the Messenger of Allah (peace and blessings be upon him), he (peace and blessings be upon him) became extremely angry. Banu Ka'b hurried to Sayyiduna Abu Bakr, Sayyiduna Umar and the other Companions of the Messenger of Allah (peace and blessings be upon him) (may Allah be pleased with them) so that they would intercede for them with the Prophet (peace and blessings be upon him). When evening came, he (peace and blessings be upon him) stood among the people and praised Allah as befits Him, then said: "Amma ba'd (to proceed): Indeed, Allah has made Makkah sacred; people did not make it sacred. Allah made it lawful for me only for an hour of a day, yesterday; then it is sacred just as Allah made it sacred. And indeed, the most hostile of people toward Allah are three: one who kills in it, and one who kills someone other than the killer (of his slain relative) for some vengeance of the Jahiliyyah. And by Allah, I will certainly pay the blood money of this man whom you have killed." Abu Shurayh (may Allah be pleased with him) said: Then the Messenger of Allah (peace and blessings be upon him) paid his blood money.
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18720