Should the debt be repaid according to today's dollar value or in Syrian Pounds, knowing that the loaned amount was in Syrian Pounds and equivalent to two thousand dollars, and the value of the dollar has significantly risen against the Lira?

Since the agreement stipulated that the loan was in Lira, and the creditor paid in dollars as an agent for exchanging them into Lira, and the exchange was made according to what was agreed upon, the debt is in Lira. The debtor must repay an amount equivalent to what he received from the exchange, which is one hundred thousand Lira.

The general principle is that if a loan has an equivalent, it should be repaid with its equivalent. This applies to currencies, unless they become unavailable in the market, in which case they should be repaid at their value on the day the payment was due and the currency became unavailable.

If they agree at the time of repayment that it should be in dollars, there is no harm, provided that the exchange rate of the Syrian currency on the day of repayment is taken into account, not on the day of the loan, and that the exchange takes place in the same session of the contract, according to the saying of the Prophet (peace be upon him): "There is no harm in taking the price of its day, as long as you do not separate while there is still something between you."

If the debtor wishes to be generous to the one who lent him, and gives him more than his due, there is no harm in that. This is considered good repayment, according to the saying of the Prophet (peace be upon him): "The best among you are those who are best in repayment."

As for borrowing for an indefinite period, its ruling has been explained previously.