Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: Hudhayl killed a man of Banu Layth at the time of the Conquest of Makkah, in retaliation for a killing from the days of the Jahiliyyah. Then (the narrator) narrated the complete previous hadith, and (the Prophet (peace and blessings be upon him)) also said: "Whoever has someone of his killed has the choice: either he takes retaliation or he takes blood money."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16041