The third pillar of Islam is Zakat, if the shahada is an act of the tongue, confirming the belief of the heart and the salat is a worshiping with the limbs of the whole body, zakat is a form of worship of Allah with your own wealth.
Zakat means purification: purification of wealth, which is the payment of 2.5 percent of accumulated wealth, and this is the wealth that has been stored, without having given movement of it, for a whole year. The payment of the Zakat is obligatory when the accumulated amount exceeds 20 gold dinars, or in the case of silver, if more than 200 dirhams or the equivalent in local currency. In this case the saved wealth is money. If the accumulated wealth are cattle or agricultural crops or stored goods for trading, a portion is also removed of it, after a whole year, to be distributed as Zakat.
In the case of agricultural production, payment of zakat is in the time of collection of the fruit or crop fields.
The payment of Zakat is a form of worship that is done with your own wealth. It is a purification of the wealth, which makes it increase, and the purification of the heart of been attach to the property, which makes wealth a blessing.
Zakat is collected by the authority of each Muslim community and also distributed by the emir or caliph or persons designated by him. Unlike what is known as Sadaqa which are voluntary and arbitrary charities given spontaneously and freely. By contrast, the Zakat is a right of the needy on the wealth of the wealthy.
This is the pillar of Islam which is more weakened today, due largely to the almost total disappearance of the Muslim form of government and social organization. It is the obligation and duty of all Muslims to restore this pillar of Islam and we ask Allah to give us strength for it.