Musannaf Ibn Abi Shayba 27:324

Abu Usama narrated to us, from Hisham, from Muhammad, who said: Two men mentioned Uthman. One of them said, "He was killed as a martyr." The other grabbed him and brought him to Ali and said, "This man claims that Uthman ibn Affan was killed as a martyr." He (Ali) said, "Did you say that?" He replied, "Yes. Do you not remember the day I came to the Prophet, peace and blessings of Allah be upon him, while Abu Bakr, Umar, and Uthman were with him? I asked the Prophet, peace and blessings of Allah be upon him, and he gave me. I asked Abu Bakr, and he gave me. I asked Umar, and he gave me. And I asked Uthman, and he gave me." "I then said, 'O Messenger of Allah, supplicate to Allah to bless me.' He said, 'And why would you not be blessed when a Prophet, a Truthful One (Siddiq), and two martyrs have given to you?'" Ali said, "Leave him, leave him, leave him."