Zakat is one of the pillars in Islam. Among the dalil for the duties in this ibadah is as mentioned in the Qur'an:

"And perform As-Salat (Iqamat-as-Salat), and give Zakat and obey the Messenger (Muhammad s.a.w.) that you may receive mercy (from Allah)" An-Nur:56

When someone performs the zakah, he has already cleanse his maal or wealth he owns as firman Allah s.w.t.:

"Take sadaqah (alms) from their wealth in order to purify them and sanctify them with it, and invoke Allah for them. Verily! Your invocations are a source of security for them; and Allah is All-Hearer, All-Knower." At-Taubah:103

To purify means ridding ourselves from being individualistic, greedy in ones self, while in the eyes of the poor(miskin), it is a way to purify ones self from having vengeance, jealousy, envious towards the wealthy. Cleansing one self brings about returning the rights of the poor(miskin) that has been enshrined in the wealth or income of someone. This is further cleared by Allah as follows:

"And in their properties there was the right of the Sail (the beggar who asks) and the Mahrum (the poor who does not ask others)" Adz-Zaariat:19

In this respect, as a muslim, it is our duty to perform the zakah when we have fulfilled the conditions.