Musannaf Ibn Abi Shayba 18:856

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us, from Hammad, from Ibrahim: He said: Ali and al-Zubayr disputed regarding the patronage (wala’) of the freed slaves of Safiyyah. So Umar judged the inheritance to al-Zubayr, and the blood money (diya) upon Ali.