Musannaf Ibn Abi Shayba 37:589

Abu Usama narrated to us, from Hisham, from Muhammad, who said: Hudhayfah said when Uthman was killed: "O Allah, if the Arabs attained good, guidance, or Your pleasure by their killing of Uthman, then I am innocent of it and have no share in it. And if the Arabs erred by their killing of Uthman, then You know my innocence." He said: "Consider what I say to you: By Allah, if the Arabs attained [something] by their killing of Uthman, they will surely milk milk from it. And if the Arabs erred by their killing of Uthman, they will surely milk blood from it."