Hazrat Ibn Umar (may Allah be pleased with them both) narrates that I used to trade gold for silver and silver for gold. I presented myself before the Noble Prophet (peace and blessings be upon him) and asked him about this matter. The Prophet (peace and blessings be upon him) said: When you trade with your companion, do not separate from him as long as there is any uncertainty between you.

Hazrat Ibn Umar (may Allah be pleased with them) narrates that when you trade with dinar, do not leave the place until you have received the payment.

Hazrat Umar (may Allah be pleased with him) said: If someone asks you for a respite even as long as it takes to milk a she-camel (in the transaction of currency exchange), do not grant him respite.

Hazrat Talha received dinars in exchange for silver, so Hazrat Umar (may Allah be pleased with him) forbade him, saying: Do not separate from him until you have received the full price.

The Noble Prophet (peace and blessings be upon him) said: "Usury is in deferred payment."

Hasan and Hazrat Ibn Sirin (may Allah have mercy on him) say that when you trade gold for silver, do not separate as long as there is a condition between you, unless it is in cash.

Hazrat Ibn Umar (may Allah be pleased with them) was asked about selling gold on credit. He replied: I heard Hazrat Umar bin Khattab (may Allah be pleased with him) on this pulpit being asked about it. He said: Whatever period of time he has given as credit, all of it is usury.

Ibrahim says that the buyer and the seller will not separate until they have concluded whatever is between them (completed the transaction).

Hazrat Shurayh says that in my view, the preferred way in the transaction of currency exchange is that they should be separate and there should be no ambiguity between them.