From the base at Alexandria, the Byzantines planned to reconquer the whole of Egypt. The Muslims of Egypt sent a delegation to Madina to wait on Uthman, and prevail on him to restore 'Amr b Al 'Aas to the command of Egypt for he alone could save Egypt for the Muslims.
Uthman summoned 'Amr b Al 'Aas , and appealed to him to take over the command of Egypt. He stipulated some terms which were accepted by Uthman. 'Amr b Al 'Aas was made the Governor of Upper as well as Lower Egypt, and he was also to be the supreme commander of the military forces in Egypt. Abdullah b Saad was to hold a subordinate position under 'Amr b Al 'Aas .
"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