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Related to this question, what if after deciding to donate Tzedaka to a cause, but before actually getting to do it, the cause goes away. E.g. the poor person dies, the organization closes down, etc.
Should the money be giving to a different place? Does there have to be a similarity between them (e.g. if it was intended for a poor person, find another poor person, don't donate it to a seforim library).