Sadaqah (giving in charity) is a deed designed to eliminate the spiritual malady of miserliness. But because the heart of the giver is not immune to show and insincerity, it has been emphasized that Sadaqah should always be given secretly. Certainly, Riyaa (ostentation) and miserliness are both very destructive diseases and Sadaqah that is rendered secretly is a powerful remedy for them.
Sadaqah also describes a voluntary charitable act towards another being, whether through generosity, love, compassion or faith. These acts are not necessarily physical or monetary. Simple good deeds such as a smile, or a helping hand, are seen as acts of Sadaqah.
For our own success, we should spend time, money and efforts in giving sadaqah for the pleasure of Allah as the rewards of sadaqah is nothing but success, especially in the Hereafter:
“The likeness of those who spend for Allah’s sake is as the likeness of a grain of corn, it grows seven ears every single ear has a hundred grains, and Allah multiplies (increases the reward of) for whom He wills, and Allah is sufficient for His creatures’ needs, All-Knower).” (Qur’an, 2:261)
“Those who (in charity) spend of their goods by night and by day, in secret and in public have their reward with their Rabb (only God and Sustainer). On them shall be no fear nor shall they grieve.” (Qur’an, 2:274)