What is the ruling on a debtor procrastinating in repaying a debt in order to take advantage of the currency's depreciation, and is he entitled to do so?

If the debtor is a procrastinator and capable of repayment upon the due date of the debt, then he is an oppressor; based on the saying of the Prophet, peace be upon him: "Procrastination [in repayment] by the wealthy is injustice." However, if he is in hardship, he must be granted a deferment, and it is not permissible to demand payment from him, as Allah Almighty says: "And if there is one in hardship, then grant him a respite until a time of ease." It is not permissible to supplicate against the debtor unless he is an oppressor and a procrastinator. The principle in debt is that it should be repaid with its equivalent, not its value, unless the currency's value has significantly and oppressively decreased. In this case, the value of the currency is taken into account if there is egregious deception or a collapse of the currency.