ALLAH swt said in Holy Quran: 2:277
“Those who believe, and do deeds of righteousness, and establish regular prayers and regular charity, will have their reward with their Lord: on them shall be no fear nor shall they grieve.”
This holy verse has described the status of zakat (charity) and the reward attached with it. Wherever in Quran ALLAH asked us to establish prayer the next order is to pay zakat. Zakat is the purifier of the yearly earnings. And this purifier is not a huge amount but only 2.5 percent of the total yearly earnings of a person. But one thing should be kept in mind that on money that is earned from haram sources, no zakat is applicable on that earning and neither can it purify the black money.
ALLAH swt said in Quran: 7:156
"----My mercy encompasses all things, but I will specify it for the righteous who ward off (evil) and pay the poor-due "
Thus, the mercy of ALLAH swt is especially for those who do not hesitate to purify their maal by taking out due share of the poor. Zakat is not necessary to be paid for those who have not much earning. Only those who earn well above their needs, or own a specific amount of money, gold or silver or property (called nisab). But many people exclude many of their owned items to cut down the zakat. They do not do not harm to the poor, because the rizq comes from ALLAH but the mischief makers forget it while accumulating wealth unjustly.
ALLAH swt says in Quran: 9: 60
“The alms are only for the poor and the needy, and those who collect them, and those whose hearts are to be reconciled, and to free the captives and the debtors, and for the cause of Allah, and (for) the wayfarer; a duty imposed by Allah. Allah is Knower, Wise.”
This verse indicates that where to use zakat and who are entitled to receive zakat. ALLAH says that it is a duty imposed on us by Him, and just by paying this small share we can fulfill our duty and can enter the gate of the mercy of ALLAH swt.
In another place ALLAH swt says: 6:141
“And it is He Who produces gardens trellised and untrellised, and date¬palms, and crops of different shape and taste (their fruits and their seeds) and olives, and pomegranates, similar (in kind) and different (in taste). Eat of their fruit when they ripen, but pay the due thereof (its Zakât, according to Allâh's Orders 1/10th or 1/20th) on the day of its harvest, and waste not by extravagance. Verily, He likes not Al-Musrifûn (those who waste by extravagance)”
The verse quoted above says that we are ordered to take the share of the poor from our earnings, but we are not told to waste it by spending it unnecessarily. Therefore, along with purifying the money, we should also take care that if we are spending what we are given in a right way!
Zakat is not just a charity but behind it is a beautiful and flawless logic of a powerful economic system. Today, the economic system is measured by the consumption of a family unit per month. If we give zakat, it will make the poor able to eat thrice a day, and in this way, the consumption will increase raising the economy over all. Another important economical impact that can be seen from zakat is the circulation of money. When more sahib-e nisab people will pay zakat, more money will move downward and this money will again move upward by GDP which will automatically change the economic health of the economy. Hence behind the zakat, is not just swab but also immense worldly benefits. All we need is to be honest with our own selves when it comes to obeying ALLAH swt.