What is the ruling regarding the Zakat al-Fitr due on slaves owned by a bankrupt person who died before the distribution of his estate to creditors?

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The Zakat al-Fitr due on the slaves of a bankrupt person who died before their distribution to creditors falls upon the heirs. This is because the debt does not prevent the transfer of the estate; rather, it functions as a pledge (rahn) for the debt. The responsibility for the Zakat of a pledged item rests upon its owner.