then this is not permissible. For if he raises the bid, he cannot himself purchase it; thus, by raising it, he harms the prospective buyers and makes matters difficult for them. So long as you know that you cannot purchase it, you may not raise the bid.

But if the principal authorizes the agent to purchase it, then he may raise the bid. Once the principal has authorized the agent to buy it, there is no harm in this. Thus, if he raises the price, he has raised it in a manner for which he has been authorized, and it is therefore valid.

His statement: “Nor may he sell it for commodities.” For example, he says, “I appoint you to sell the car,” and you sell it for an apartment. The car is worth ten thousand, while the apartment is worth fifteen thousand. This is not permissible, because when I say, “Sell it,” I mean for cash; I do not mean, “Sell it for a house.”

Another example: he says, “Sell this car,” so the agent goes and sells it for another car. This is not permissible, because when I say, “Sell it,” I mean sell it for cash, not for commodities—and so on.

In the terminology of the jurists, copper coins are considered commodities, and paper currency is likewise considered a commodity, because currency in their view consists only of dirhams and dinars—that is, silver and gold. Accordingly, paper currency would be classified by the jurists as a commodity. Should we then say that the author’s words indicate that, if I say, for example, “Sell this house,” and he sells it for ten thousand in paper currency, the sale is not concluded because he sold it for commodities? We say: this is what the author’s words entail, for they explicitly stated that he may not sell it for copper coins. However, we say that paper currency has now come to serve among people in place of dinars and dirhams. Therefore, if he sells it for money—that is, paper currency—the sale is valid.