Thus, the various parts of one and the same animal are distinct genera, each part constituting an independent genus. On this basis, it is permissible to sell some of them for others in unequal amounts. But must possession be taken by both parties?

The answer is yes, because they share the same legally prescribed measure: all meat is weighed. Since they share the same legal measure, both parties must take possession before separating. Equality, however, is not a condition.

His statement: “It is not valid to sell meat for a live animal of the same genus, but it is valid for an animal of a different genus.”

For example, if I have a heap of sheep meat and wish to sell it for a sheep, this is not permissible, because it is of the same genus.

If someone were to say: What I have is meat, whereas the sheep or lamb contains liver, heart, and lung, and you have stated that each of these things is an independent genus?

We reply: If what you have is meat, and the sheep contains meat, then you have sold meat for meat along with something of a different genus. This falls under what the jurists call the case of a mudd of dates and a dirham, and it is therefore not permissible.

Likewise, if I sell you ten sāʿs of dates for two sāʿs of dates together with eight sāʿs of barley, this is not permissible, because you have sold one genus for the same genus together with something of another genus. This is the issue of a mudd of dates and a dirham in exchange for a mudd of dates, or for two mudds of dates and a dirham, as will come, Allah willing.

Thus, the author states that selling meat for a live animal of the same genus is not permissible.

He cited the following evidence: