Sadaqah is an Arabic term widely used to cover all kinds of charity. Although Sadaqah and Zakat are often used interchangeably, Sadaqah voluntary or optional charity.
All good deeds are considered Sadaqah. Every Muslim is exhorted to give Sadaqah. The Prophet Muhammad(S) said:
“Every Muslim has to give Sadaqah.” The people asked: “O Prophet of Allah, what about the one who has nothing?” He(S) replied: “He should work with his hand to give Sadaqah.” They asked: “If he cannot find (work)?” He(S) replied: “He should help the needy who asks for help.” They asked:” If he cannot do that?” He (S) replied: “He should then do good deeds and shun evil, for this will be taken as Sadaqah.” (Sahih al-Bukhari)
Muslims practice Sadaqah and earn rewards from Allah by doing good deeds all their lives. They can continue earning Allah’s rewards even after their death should they leave any of the following legacies behind them. This is called perpetual Sadaqah (Sadaqat-ul-Jariyah). Prophet Muhammad (S) is reported to have said:
“When a person dies (the benefit) of his deeds ends, except three: a continuous Sadaqah, knowledge from which benefit is derived, or a pious child invoking Allah for him.” (Sahih Muslim & Ahmad)