1؎: For example, if a salam sale (forward sale) is made to receive wheat, and before taking possession of the wheat, he agrees to receive rice in its place, then this is not permissible.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues: Benefit: This narration is weak in its chain of transmission. In such a case, if the seller is genuinely unable to provide the goods at the appointed time, then he should return the amount received. Or they should come to a suitable reconciliation in an appropriate manner.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 3468