Read all Ahadith in the book of zakat by sahih al bukhari

Narrated Ibn `Abbas: The Prophet (saws) sent Mu`adh to Yemen and said, Invite the people to testify that none has the right to be worshipped but Allah and I am Allah's Apostle, and if they obey you to do so, then teach them that Allah has enjoined on them five prayers in every day and night (in twenty-four hours), and if they obey you to do so, then teach them that Allah has made it obligatory for them to pay the Zakat from their property and it is to be taken from the wealthy among them and given to the poor.

Narrated Abu Aiyub: A man said to the Prophet Tell me of such a deed as will make me enter Paradise. The people said, What is the matter with him? What is the matter with him? The Prophet said, He has something to ask. (What he needs greatly) The Prophet said: (In order to enter Paradise) you should worship Allah and do not ascribe any partners to Him, offer prayer perfectly, pay the Zakat and keep good relations with your Kith and kin. (See Hadith No. 12, Vol 8).

Narrated Abu Huraira: A Bedouin came to the Prophet and said, Tell me of such a deed as will make me enter Paradise, if I do it. The Prophet (p.b.u.h) said, Worship Allah, and worship none along with Him, offer the (five) prescribed compulsory prayers perfectly, pay the compulsory Zakat, and fast the month of Ramadan. The Bedouin said, By Him, in Whose Hands my life is, I will not do more than this. When he (the Bedouin) left, the Prophet said, Whoever likes to see a man of Paradise, then he may look at this man. Narrated Abu Zur'a: From the Prophet the same as above.

Narrated Ibn `Abbas: A delegation of the tribe of `Abdul Qais came to the Prophet and said, O Allah's Apostle! We are from the tribe of Rabi`a, and the infidels of the tribe of Mudar stands between us and you; so we cannot come to you except during the Sacred Months. Please order us to do something (religious deeds) which we may carry out and also invite to it our people whom we have left behind. The Prophet said, I order you to do four things and forbid you four others: (I order you) to have faith in Allah, and confess that none has the right to be worshipped but Allah, (and the Prophet gestured with his hand like this (i.e. one knot) and to offer prayers perfectly and to pay the Zakat, and to pay onefifth of the booty in Allah's Cause. And I forbid you to use Dubba', Hantam, Naqir and Muzaffat (all these are the names of utensils used for preparing alcoholic drinks).

Narrated Abu Huraira: When Allah's Apostle died and Abu Bakr became the caliph some Arabs renegade (reverted to disbelief) (Abu Bakr decided to declare war against them), `Umar, said to Abu Bakr, How can you fight with these people although Allah's Apostle said, 'I have been ordered (by Allah) to fight the people till they say: None has the right to be worshipped but Allah, and whoever said it then he will save his life and property from me except on trespassing the law (rights and conditions for which he will be punished justly), and his accounts will be with Allah.'

Abu Bakr said, By Allah! I will fight those who differentiate between the prayer and the Zakat as Zakat is the compulsory right to be taken from the property (according to Allah's orders) By Allah! If they refuse to pay me even a she-kid which they used to pay at the time of Allah's Apostle . I would fight with them for withholding it Then `Umar said, By Allah, it was nothing, but Allah opened Abu Bakr's chest towards the decision (to fight) and I came to know that his decision was right.

Narrated Jarir bin `Abdullah: I gave the pledge of allegiance to the Prophet for offering prayer perfectly, giving Zakat, and giving good advice to every Muslim.

Narrated Abu Huraira: The Prophet said, (On the Day of Resurrection) camels will come to their owner in the best state of health they have ever had (in the world), and if he had not paid their Zakat (in the world) then they would tread him with their feet; and similarly, sheep will come to their owner in the best state of health they have ever had in the world, and if he had not paid their Zakat, then they would tread him with their hooves and would butt him with their horns. The Prophet added, One of their rights is that they should be milked while water is kept in front of them. The Prophet added, I do not want anyone of you to come to me on the Day of Resurrection, carrying over his neck a sheep that will be bleating. Such a person will (then) say, 'O Muhammad! (please intercede for me,) I will say to him. 'I can't help you, for I conveyed Allah's Message to you.' Similarly, I do not want anyone of you to come to me carrying over his neck a camel that will be grunting. Such a person (then) will say O Muhammad! (please intercede for me). I will say to him, I can't help you for I conveyed Allah's message to you.

Narrated Abu Huraira: Allah's Apostle said, Whoever is made wealthy by Allah and does not pay the Zakat of his wealth, then on the Day of Resurrection his wealth will be made like a baldheaded poisonous male snake with two black spots over the eyes. The snake will encircle his neck and bite his cheeks and say, 'I am your wealth, I am your treasure.' Then the Prophet recited the holy verses:-- 'Let not those who withhold . . .' (to the end of the verse). (3.180).

Narrated Khalid bin Aslam: We went out with 'Abdullah bin 'Umar and bedouin said (to 'Abdullah), Tell me about Allah's saying: And those who hoard up gold and silver (Al-Kanz - money, gold, silver etc., the Zakat of which has not been paid) and spend it out in the Way of Allah (V.9:34). Ibn 'Umar said, Whoever hoarded them and did not pay the Zakat thereof, then woe to him. But these holy Verses were revealed before the Verses of Zakat. So when the Verses of Zakat were revealed Allah made Zakat a purifier of the property.