مسائل المنتخبه (Articles Of Islamic Acts) - الخوئي، السيد أبوالقاسم - الصفحة ٦٢٤ - Current Issues

These are the orders relating to the Islamic banks. As regards the banks belonging to the non Muslims, however, property may be obtained from them without the intention of taking loan and withoutobtaining permission for doing so from the mujtahid. Nevertheless, as regards depositing money in such banks, the same rules apply to them as they apply to the Islamic banks.
LETTER OF CREDIT FOR EXPORT
٢٨٦١. It is lawful for one to obtain an L/C from a bank for import and export business and it is also apparently lawful for a bank to provide foreign exchange onpayment of commission and to charge commission, because from the point of view of jurisprudence such a commission will either be called wage or agreement and it isalso possible to treat it as sale and purchase. As the bank pays the price of the goods by means of foreign currency it is possible that the bank may sell the foreigncurrency payable by an importer at such a price that it may also earn its own commission from it and as the transaction takes place with regard to two different things it isin order. In this regard another alternative can be that tile persons engaged in import and export business may obtain information through the bank and then the bank maycontinue to provide the goods and pay its price on the basis of L/C. In such circumstances it will also be lawful.
٢٨٦٢. If the bank pays the price of the imported goods on behalf of the L/C holder and does not treat it as loan advanced

because a businessman hires a bank for a particular task. In case, however, the bank is not a domestic one the hiring will be valid only with the permission of the mujtahid or his representative(wakil).
To promise payment of some amount on ones performing a particular task.