Whoever has property must pay its proper zakah. If the property is indebted, he may first pay off his debt, then in case the remainder is enough to constitute a nisab, he must pay zakah. If he does not hold the nisab, he does not have to pay it since he is poor. The Messenger of Allah, upon whom be peace, said: “Only the wealthy are required to give charity.” This hadith is related by Ahmad and al-Bukhari. The latter records it in mu’allaq form. The Prophet also said: “Zakah is levied on the rich and paid to the poor.” It is all the same, whether he is indebted to Allah or to man, because one hadith states: “Allah’s debt is more deserving of fulfilment.”
Section : The Insolvent Debtor.