Mālik. Ahmad allowed greater latitude in this matter than Mālik.

The view mentioned by al-Khiraqī and others has been described as another position transmitted from Ahmad, as reported by Ibn Abī Mūsā and others. The correct view is that this is permissible, for there is no evidence prohibiting it. And Allah knows best.

He was asked:

If a man pays in advance for something under a salam contract, may he accept something else from the seller? For example, if he pays in advance for wheat, may he accept barley in its place, whether or not the contracted goods can be delivered?

He replied:

If someone pays in advance for wheat and accepts barley in its place, or makes a similar substitution, scholars hold two views on this.

The first is that accepting something else in place of the goods owed under a salam contract is impermissible. This is the position of Abū Hanīfah and al-Shāfiʿī, and one of the two positions transmitted from Ahmad.

The second is that such substitution is permissible in principle, provided it is at the current market price or less. This is what is reported from Ibn Abbās: he permitted someone who had paid in advance for something to accept a substitute of equivalent value, without making a profit twice. This is also the other position transmitted from Ahmad, who permitted accepting barley in place of wheat, provided its value was no greater than