He was asked:

“What of a group of people who sell for dirhams, settle part of the amount in copper coins as a concession, and then report the price as the stipulated price?”

He replied:

They may not pay in copper coins without the seller’s consent. When they do pay in copper coins, they may do so only at the prevailing exchange rate, in accordance with the Prophet’s instruction, peace and blessings be upon him, to Abd Allāh ibn Umar. He had said to him, “We sell for gold and collect payment in silver, and sell for silver and collect payment in gold.” The Prophet replied:

“There is no harm in that at the exchange rate on that day, provided you part with nothing remaining outstanding between you.”

In that case, the choice of currency for the price makes no difference in valuation, for this is profit on something for which no liability has been borne. On this understanding, all debts and their settlement in an alternative form are alike, because the two valuations operate in the same way. Receiving either currency in settlement of the other is therefore like receiving that currency in settlement of itself. This does not constitute an exchange transaction, so no stipulated increase is permissible, just as it is impermissible in a loan and similar transactions requiring equivalence.

Thus, if they agree that one of them will pay more than its value, this is like agreeing