Is a deceased father who incurred debt to prepare his daughter for marriage considered among those in debt (al-gharimin) who are eligible to receive Zakat? And is the Zakat paid to his family valid if it is later discovered that the promissory notes were forged?

If a man dies in debt and leaves no assets to cover his debt, he is considered among the ghaarimeen (those in debt), and it is permissible to pay off his debt from Zakat funds. This is the fatwa issued by the Permanent Committee, based on what Al-Bukhari and Muslim narrated that the Prophet (peace be upon him) said: "There is no believer but I am the closest to him in this world and the Hereafter. Recite, if you wish: (The Prophet is closer to the believers than their own selves). So, if any believer leaves wealth, let his nearest relatives inherit it, whoever they may be. But if he leaves debt or dependants, then let him come to me, for I am his protector." If it is not possible to pay off his debt from the public treasury, then it is permissible to pay it from Zakat.

If Zakat is paid to cover a debt, and then it becomes clear that the documents proving the debt are forged, it is safer to re-issue the Zakat. Jurists have differed regarding someone who paid Zakat to a person he thought was eligible, but then it turned out otherwise. Some held that it suffices and he is not required to re-issue it, while others held that it does not suffice and re-issuance is obligatory. Some scholars have favored the opinion that it suffices if the payer made an effort and investigated diligently, because in acts of worship, what matters is the payer's belief, and Allah does not burden a soul beyond its capacity.