Translation of the verse 4 from Surah Al-Mu’minun : Number of verses 118 - - page 342 - Part 18.
And those who pay the Zakat.
And they who are observant of zakah
(23:4) who spend their Zakat dues in appropriate ways: *5
*5) The word Zakat literally means purification and development-to help something grow tip smoothly and develop without obstruction. As an Islamic term, it implies both the portion of wealth taken out for the purpose of purifying the rest of wealth and the act of purification itself. The words of the original Text mean that the Believer constantly practises purification. Thus the meaning is not confined to the paying off of Zakat dues only but it is extended to self-purification which includes purification of morals as well as wealth, property and life in general. Then it does not mean purification of one's own self, but includes the purification of the lives of other people as well. So the verse means: "The Believers are the people who purify themselves as well as others." This thing has been stated at other places in the Qur'an -also, for instance: "Successful is he who practised -purification and remembered his Lord and prayed." (LXXXVII: 1415), and: "Successful is he who purified himself and failure is he who corrupted it." (XCI: 9-10). But this verse is more comprehensive in meaning because it stresses the purification of both society and one's own person.
Source : Al-Mu’minun Verse 4: And they who are observant of zakah