DEBT. In Muslim law there are two words used for debt. Dain (دين) , or money borrowed with some fixed term of payment, and qarzفرض , or money lent without any definite understanding as to is repayment. Imprisonment for debt is allowed. (Hidayah, vol. ii, p. 624.)
Upon the decease of a debtor, the law demands that after the payment of the funeral expenses, his just debts must be paid before payment of legacies.
To engage in a Jihad or religious war, is said by Muhammad to remit every sin except that of being in debt. [JIHAD, DAIN, QARZ.]

Based on Hughes, Dictionary of Islam