'Amr b Al 'Aas belonged to the Sahm section of the Quraish. When the Holy Prophet declared his mission, 'Amr was one of the great opponents of Islam. He even planned the murder of the Holy Prophet. When some of the Muslims migrated to Abyssinia, the Quraish sent a delegation to Abyssinia to prevail upon the Negus to expel the Muslims from his State. 'Amr was one of the members of this delegation. 'Amr was an active member of the delegation, but the delegation failed in its object. At the battle of Uhud, 'Amr commanded the Quraish cavalry.
"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