Is it permissible to consider a debt as part of Zakat al-Mal (charitable alms)? Is Zakat obligatory upon the lender regarding the money he has lent? Is it permissible for the mortgagor to mortgage his land in exchange for a debt, even if its value is greater?

There is no harm in mortgaging land in exchange for borrowed money, even if the value of the land is greater than the value of the debt, provided the debtor agrees to it. The debtor must repay the debt when it becomes due, if capable, and it is not permissible for him to procrastinate. Furthermore, he must sell what exceeds his basic needs to repay the debt if the creditors do not grant him an extension.