His statement, “or at whatever price the bidding ends at”: that is, “I sell it to you at the price reached in the bidding.” This is not valid, because we do not know whether it will end at a high price or a low one. Someone may come and artificially bid up the price, or there may be few people present and the price may fall. For this reason, it is not valid to sell it at whatever price the bidding ends at.

It has also been said that it is valid, and that selling it at whatever price the bidding ends at gives greater assurance than selling it through bargaining. A person may feel reassured and say, “Since people have settled on this price, that indicates that it corresponds to the item’s value.” Yet there remains some reservation about this.

The stronger view is that it is not valid to sell at whatever price the bidding ends at, because the price at which the bidding ends is unknown. If artificial bidding occurs, it rises; and if those present are few, it falls. Thus, the uncertainty remains. For this reason, it should not be sold at whatever price the bidding ends at.

His statement, “or at the price for which Zayd sold it: if they, or one of them, do not know it, it is not valid”: this is because the price at which Zayd sold it is unknown, and this is the madhhab. It has also been said that it is valid, because it can be ascertained by referring back to Zayd. And it has been said that if Zayd is someone whose assessment of prices is relied upon, then selling at the price for which he sells is valid. For example, Zayd is well known in the town and recognized as someone who knows market prices, so the seller says, “I sell it to you at the price for which Zayd sells.”