The Cow - 2:177
It is not good that you turn your faces towards the east or the west. The righteous are those who believe in Allah, the Last Day, the angels, the Book and the Prophets, and they give freely to relatives, orphans, the needy, the stranded, the beggars, and to free the slaves, and they observe the prayer, and pay the zakat, and keep their word when they contract, and they resist hardship, distress and oppression. It is they who are the righteous, and it is they who are the virtuous.
The importance of zakat:
The Cattle/6:16
Whoever is turned away from torment on that Day, (God) has mercy on him. That is the greatest victory.
The Heights/7:156
"Write for us good in this world and in the Hereafter. We turn to you."He said: "My punishment will touch whom I will. But My Mercy is all-encompassing; I will write it especially for those who lead a righteous life, pay the zakat and believe in Our verses."
The Romans/30:39
The usury money which you give to increase in the wealth of the people does not increase with Allah. But as for the zakat which you give seeking Allah´s Pleasure, those who give it multiply their investment.
The Hypocrites/63:10
"Give out of what We have provided for charity before death comes to you and you say, "My Lord, if only You would postpone me for a short time so that I may be of the righteous by helping the poor"."