Musnad Abu Ya'la al-Mawsili 152:142

Abu Khaythama narrated to us, Muhammad ibn Khazim narrated to us, from Hajjaj, from Zayd ibn Jubayr, from Khashf ibn Malik, from Abdullah: That the Messenger of Allah (may Allah bless him and grant him peace) set the blood money (diyah) for accidental killing into fifths.