Once seven persons went on a journey. After some time six of them returned, and they could give no news about the seventh man. They gave conflicting accounts about him. Sometimes they said that he had died. Sometimes they said that he had quarreled with them and left their company. The wife of the man suspected that they had killed her husband. She accordingly lodged a complaint in the court of Ali. Ali summoned the six men. Each one of them was kept in a separate room where a security guard was posted. Thereafter one of them was called to the presence of Ali. The man was charged with murder, but he insisted that he was innocent and knew nothing about the man. Thereupon Ali ordered the court crier that he should give the "Azan". As the "Azan" sounded, the other persons segregated in the various rooms shuddered and thought that their companion had confessed the murder. Accordingly, when they were summoned and presented before Ali, they confessed their guilt. Ali accordingly ordered them to pay "Qasas" to the widow of the murdered person.
"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