Is it permissible to buy dollars from the black market with a certified check for its value in Libyan dinars, knowing that the price of the dollar with a check is higher than its cash price, due to its unavailability in banks and the inability to withdraw money from them?

According to the majority of contemporary scholars, banknotes are considered analogous to gold and silver. Immediate possession (hand-to-hand exchange) is required when different currencies are exchanged, based on the hadith (definition): "If these types [of commodities] differ, then sell as you wish, provided it is hand-to-hand."

A certified check holds the ruling of possession, so it is permissible to purchase currency with it. However, if the bank does not have the liquidity, then the check does not hold the ruling of possession, and it is not permissible to purchase currency with it, because the amount then becomes a debt owed by the bank.