Is it obligatory to donate the exact amount contributed to the construction of a building, or should a percentage of the profit from its sale be added to it when there is doubt about the source of the money? And is it obligatory to immediately donate money earned from working in a bank after deciding to leave it, or can it be postponed and paid in installments?

The excuse for the questioner regarding his previous work has been clarified, and there is no harm for him in benefiting from what he earned from it. He should cease indulging in further questions and doubts. As for what the questioner intended to donate as charity, he is not bound by anything specific; rather, the matter is subject to his will. If he wishes, he may donate the amount he intended, or more, or less, and either in installments or all at once. Jurists have unanimously agreed that if someone intends to give a specific amount as charity and begins to donate part of it, he is not obligated to donate the remainder. And if someone sets aside something to donate as charity but then changes his mind, it is recommended, though not obligatory, for him to proceed with it, because the recipient does not own the money until it is physically received.