The evidence from the Quran is the statement of Allah, Most High:

“And what prevents their expenditures from being accepted from them except that they have disbelieved in Allah and His Messenger, that they do not come to prayer except lazily, and that they do not spend except unwillingly.” [al-Tawbah 9:54]

If their expenditures are not accepted, then there is no benefit in compelling them to give them. Nevertheless, they will be brought to account for them on the Day of Resurrection and punished for them.

The evidence for this is Allah’s statement concerning the criminals:

“What put you into Saqar?” They will say, “We were not among those who prayed, nor did we feed the poor. And we used to indulge in vain discourse with those who indulged in it.” [al-Muddaththir]

Had they not been punished for abandoning the prayer and for failing to feed the poor, they would not have mentioned these as reasons for entering the Fire.

3—Possession of the nisab, the minimum threshold upon whose attainment the Lawgiver has made zakah obligatory. It differs according to the type of wealth, so one must possess the nisab. If a person owns nothing, like a poor person, then nothing is due from him; and if he owns less than the nisab, then nothing is due from him.

The evidence that possession of the nisab is a condition is the Prophet’s statement, peace and blessings be upon him: “There is no zakah on less than five awsuq, no zakah on less than five awaq, and no zakah on less than five camels.” (1) He also said regarding sheep: “When they reach forty sheep, one sheep is due.” (2) There are other proofs as well. This is because an amount below the nisab is insufficient to accommodate charitable assistance.

4—Its stability; that is, the stability of ownership.