Musannaf Ibn Abi Shayba 38:25

Yahya ibn Adam narrated to us, he said: Ibn 'Uyaynah narrated to us, from Isma'il ibn Abi Khalid, from Hakim ibn Jabir, he said: I heard Talhah ibn 'Ubayd Allah on the day of the Camel saying: "We had been compromising regarding the affair of 'Uthman, and we found no escape from giving the pledge of allegiance."