After the Holy Prophet had delivered the address, Allah revealed to him the verses: "This Day have I perfected for you, your faith, and completed My blessings upon you, and have chosen for you Islam as religion. "All other prophets including Moses and Jesus Christ had to leave their unfulfilled mission to their successors. The Holy Prophet of Islam alone had the unique distinction of seeing the successful fruition of his mission during his lifetime.
"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