Is the thief obligated to return the exact amount he stole twenty years ago, even though the currency has depreciated, and does this ruling differ from the rulings on loans and other debts?

The established right owed due to usurpation (ghasb), theft, or procrastination in debt repayment must be returned at its value on the day it was taken, along with guaranteeing any damage incurred to stolen physical items. As for other debts, a distinction is made between minor changes (less than one-third), in which case the like (mithl) must be returned, and significant changes (one-third or more), in which case reconciliation through the distribution of harm is necessary. If recourse is made to value, it is estimated at the price of gold or the purchasing power of the currency at the time the debt was incurred, and payment is made in a different currency.