I say, with Allah's guidance: One of the conditions for the obligation of zakat is that the responsible Muslim must be free from debt. Zakat is not obligatory on the debtor to the extent that his wealth is occupied by debt, because zakat is due on the wealthy to enrich the poor, and wealth borrowed does not constitute wealth until it is repaid. There is no difference in this between deferred and immediate debt, and the debt referred to is one that has a claimant from the people, so that a vow or expiation debt does not prevent the obligation of zakat. As narrated from Uthman ibn Affan, may Allah be pleased with him, he used to say: 'This is the month of your zakat, so whoever has a debt should pay it, so that your wealth is collected, and you can pay zakat from it.' (Referenced in Muwatta Malik 1:253, Sunan al-Bayhaqi al-Kubra 4:148, Musnad al-Shafi'i 1:97, Musannaf Ibn Abi Shaybah 2:414, and Musannaf Abdul Razzaq 4:92). And Allah knows best.