Abdullah bin Abi Bakr (may Allah have mercy on him) said that his father informed him that in the letter which the Prophet (peace and blessings be upon him) wrote for Sayyiduna Amr bin Hazm (may Allah be pleased with him) there was also this: "The diyah for a life is 100 camels."
Ibn Jurayj (may Allah have mercy on him) said: I asked Abdullah bin Abi Bakr (may Allah have mercy on him): Do you have any doubt that it is the letter of the Prophet of Allah (peace and blessings be upon him)? He said: No.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16146