Musannaf Ibn Abi Shayba 37:586

Ali ibn Hafs narrated to us, he said: Muhammad ibn Talhah narrated to us, from Asim ibn Kulayb al-Jarmi, from Abu Qilabah, he said: Al-Hasan ibn Ali came to Uthman and said, "Unsheathe my sword." He (Uthman) said, "Then I would not be free from your blood before Allah. But sheath your sword and return to your father."