Musannaf Ibn Abi Shayba 38:36

Waki’ narrated to us, from Sufyan, from Abu Ja’far, from his father, from Ali ibn al-Husayn, who said: Abbas narrated to us, saying: Ali sent me to Talha and al-Zubayr on the Day of the Camel. He said: So I said to them, "Your brother sends you greetings and says to you: 'Have you found any injustice from me in a judgment, or any monopolization of spoils, or such and such, or such and such?'" He said: So al-Zubayr said, "No, not in any of them. But along with fear, there is the intensity of ambitions."