Denying Zakat Equals Denying Faith

Malik said that a collector wrote to 'Umar bin Abdul Aziz complaining about a man who refused to pay zakat. 'Umar wrote that he should leave him alone and not take his zakat from him with the other Muslims. When the man heard of this, he felt pained and paid the zakat on his property. The collector then wrote to 'Umar making mention of this fact, and 'Umar bin Abdul Aziz wrote back (asking him) to take his zakat [Refer Muwatta Imam Malik: 1/270]