What is the ruling on leftover Zakat money that was not disbursed due to excessive scrutiny in identifying the poor, and is it permissible to disburse it now?

"Knowledge of those eligible for zakat is obtained by the poor person informing that he is eligible. So, whoever claims poverty and his condition is unknown, he is given. The poor person is not required to provide proof to establish his need, but he should be informed that this money is zakat. Zakat should not be delayed except for a slight need, such as searching for the most deserving people."