Another example: someone sells wheat for dirhams, then takes dinars instead of the dirhams. This is permissible, because wheat may be sold for dinars on deferred terms. Thus, if a man sells one hundred sa‘ of wheat for two hundred dirhams, and when the payment falls due the buyer says, “I do not have any dirhams, but I have dinars,” this is permissible, because wheat may be sold for either dirhams or dinars on deferred terms; thus, there is nothing prohibited in it.

However, the Prophet, peace and blessings be upon him, stipulated two conditions:

First: it must be at the exchange rate of that day.

Second: they must both take possession before parting.

This is because Ibn ‘Umar, may Allah be pleased with them both, asked him for a legal ruling, saying: “O Messenger of Allah, I used to sell camels for dirhams and receive dinars, and sell them for dinars and receive dirhams. Is that permissible?” He said: “There is no harm in taking them at the exchange rate of that day, so long as you do not part while anything remains outstanding between you.” (1)

Al-Muwaffaq, the author of al-Mughnī, said: It is permissible to sell a ribawi item on deferred terms and then take, in place of its price, something that may not be sold for it on deferred terms, because the legal device in this case is remote. How could someone sell wheat for dates after one year? This is far-fetched, and what is far-fetched carries no weight.