In spite of the magnanimity of Uthman, Kammil on return to Kufa continued his activities against Uthman. When in 656 C.E., a contingent from Kufa left for Madina, both Ummair and Kammil were included therein. When Uthman was assassinated Ummair and Kammil insisted that the dead body of Uthman should be mutilated. Years later when Hajjaj became the Governor of Kufa, he tried Ummair and Kammil for the murder of Uthman and had them executed.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari