In 643 C.E. Umar appointed Mugheera b Shu'ba as the Governor of Kufa. When Uthman became the Caliph, Mugheera continued in his office for one year, and was thereafter deposed to make room for the appointment of Sa'ad b Abi Waqas according to the testament of Umar.
"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