In the armory of a momin there are certain arms about which the Prophet (a.s.) has made a particular mention. The Prophet (a.s.) said:

" Fasts of a momin blacken the face of Satan. Sadaqa or charity breaks the backbone of Satan. Istaghfar-entreaty with Allah for mercy-will cut the Satan's vein of life, and love of Allah and good deeds of the person uproot Satan."-Safinat al Bihar, vol 2, page 62

When you fast the face of Satan, your enemy, will be blackened. If the curtains are raised from your eyes, you will notice that Satan's face has turned black on account of your fasts.

But Satan is not so weak and emaciated that only by fasting you get his face blackened and with a strike of charity you shatter his backbnone. You have to perform every action with absolute sincerity that they pass through the seven curtains and break Satan's backbone and destroy him.

Now let us talk about Sadaqa or charity. According to what the Prophet (a.s.) has said, it does break the backbone of Satan. But there is a condition that your charity should be acceptable to Allah.