At Tabuk, the Holy Prophet delivered a classical address which has passed into history. He said: Verily, the most veracious discourse is the Book of Allah. The most trustworthy stronghold is the word of piety. The best of religions is the religion of Islam. The best of precedents is the precedent of Muhammad. The noblest speech is the Invocation of Allah. The finest of the narrative is the Quran. The best of the affairs is that which has been firmly resolved upon. The worst in religion are those things which are created without sanction. The best of the ways is the one bidden by Prophets. The noblest death is the death of a martyr. The most miserable blindness is waywardness after guidance. The best of the actions is that which is beneficial. The best guidance is that which is put into practice. The worst blindness is the blindness of the heart.
"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