without taking any extra. If it is superior, however, he must not accept it.’” He also cited the report of Ibn ʿAbbās, transmitted by Tāwūs from Ibn ʿAbbās:

“If you pay in advance for something and the due date arrives, but you cannot find what you paid for, accept a substitute of lesser value, and do not make a profit twice.”

Ahmad ibn Asram also reported that Ahmad was asked about a man who paid in advance for food to be delivered at a specified date: when it fell due, could he purchase land or a house from the seller instead? He replied:

“Yes, he may purchase from him goods not sold by volume or weight.”

Harb al-Kirmānī said:

“I asked Ahmad, ‘A man paid another man dirhams in advance for wheat, but when delivery fell due, the seller did not have it. Some people said, “Take barley in exchange for the dirhams.”’

“He replied, ‘He may accept barley from him only in a volume equal to that of the wheat, or less.’

“I said, ‘If the wheat amounts to ten jarībs, may he accept ten jarībs of barley?’

“He replied, ‘Yes.’”

Others have transmitted the same position from Ahmad. This position occurs more frequently in Ahmad’s explicit statements and accords more closely with his principles. His reason for prohibiting the sale of goods owed under a salam contract is that they are goods already sold and therefore may not be resold before possession is taken. Yet, according to the apparent position of his school, Ahmad does not prohibit every sale before possession; rather, he makes distinctions and has several well-known positions on the matter. For this reason, he distinguished between selling back to the original seller and selling to someone else. Similarly, Mālik’s school permits exchanging the goods owed under a salam contract with their seller for a substitute worth their original price or less, but not more. This is not permissible in the case of food.

Ibn al-Mundhir said:

“It is established that Ibn ʿAbbās said, ‘If you pay in advance for something