On his death bed, Abu Bakr nominated Umar as his successor. Ali not only took the oath of allegiance to Umar but also married his daughter Umm Kulthum to Umar, and quite contrary to the biased allegations, perfect cordiality prevailed between Ali and Umar. Ali held the office of the Chief Justice. He acted as the principal Counselor of Umar. He acted as Chief Secretary as well. The services of Ali were highly appreciated by Umar. In these circumstances the views expressed in some quarters that Umar was the worst enemy of Ali is far from truth and cannot be accepted.
"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