must give him the value of wheat of equal volume to the pebble that he removed. Had he not removed the pebble, the owner would have sold his wheat together with the pebble, all for the price of wheat. Accordingly, the removal of the pebble effectively caused the owner a small loss. It is apparent from this ruling that when selling produce, a buyer accepts upon himself that a quantity of dirt may be mixed in.

The Gemara answers: With regard to legumes, one accepts a quarter-kav per se’a, but with regard to dirt, he accepts less than a quarter-kav.

And is so that he does not accept a quarter-kav of dirt? But isn’t it taught in a baraita: With regard to one who sells produce to another, if he sells him wheat, the buyer accepts upon himself that a quarter-kav of legumes may be present in each se’a of wheat purchased. When purchasing barley, he accepts upon himself that a quarter-kav of chaff may be present in each se’a purchased. When purchasing lentils, he accepts upon himself that a quarter-kav of dirt may be present in each se’a purchased.

The Gemara asks: What, is it not that just as the baraita rules with regard to lentils, the same is true for wheat and for barley? The Gemara answers: No, lentils are different, because they are dug up from the ground and dirt can easily get mixed in. Lentils often contain a higher percentage of dirt than do wheat and barley, which are harvested rather than dug up.

The Gemara suggests: But according to this, the only reason that a buyer accepts that dirt may be present in lentils but not in wheat and barley is that lentils are dug up from the ground, whereas wheat and barley are not. If so, resolve the dilemma from this baraita and conclude that when purchasing wheat and barley, a buyer does not accept that a quarter-kav of dirt may be present in each se’a.

The Gemara rejects this: Actually, perhaps when purchasing wheat and barley as well, a buyer accepts that a quarter-kav of dirt may be present in each se’a, but it was necessary for the baraita to state the halakha specifically with regard to lentils. This is because it might enter your mind to say that since lentils are dug up from the ground, the buyer would also accept even more than a quarter-kav of dirt. Therefore, the baraita teaches us that this is not the case.

§ Rav Huna says: If the buyer comes to sift the produce to check if there is more than the acceptable proportion of impurities and he finds that there is too much, he sifts all of it and returns all the impurities to the seller, not just the amount in excess of a quarter-kav per se’a. The seller must instead provide produce that is free of any impurities. Some say that this is the strict halakha, and some say that it is a penalty.

The Gemara elaborates: Some say that this is the strict halakha, as one who gives money for produce gives it for good-quality produce containing no impurities at all. Even so, where there is just a quarter-kav of impurities per se’a, a person will not take the trouble to sift the grain to remove the impurities; instead, he accepts the small quantity of impurities that are present. By contrast, where there is more than a quarter-kav of impurities per se’a, a person will take the trouble to sift the grain to remove the impurities, and once he takes the trouble to sift the grain, he does not stop once he reduces the proportion of impurities to a quarter-kav per se’a; rather, he takes the trouble to sift all of it. Accordingly, once he has sifted out the impurities, he never agrees to accept any quantity of impurities, and so the seller must take back all the impurities.

And some say it is a penalty. They understand that it is usual for a quarter-kav of impurities to be present in each se’a of produce, and so it is presumed that a buyer accepts that quantity. More than a quarter-kav is unusual, and consequently the seller is suspected of having deceitfully mixed additional impurities into the produce that he sold. And since the seller deceitfully mixed in impurities, the Sages penalized him by requiring him to pay for all of the impurities present, even those which he did not add.

The Gemara presents a mnemonic for the cases it will cite: All two documents of Ravin bar Rav Naḥman are exploitation and a contract.

The Gemara raises an objection to Rav Huna’s ruling from a mishna (Kilayim 2:1): With regard to any se’a of seeds that contains a quarter-kav or more of seeds of a different kind, before sowing such seeds one must reduce the quantity of the other kind of seeds in the mixture so as not to violate the prohibition against growing a mixture of diverse kinds (see Leviticus 19:19). The Gemara explains: It can be assumed that the presence of a quarter-kav of seeds of a different kind per se’a with regard to the prohibition of diverse kinds is as problematic as more than a quarter-kav of impurities per se’a with regard to a sale, as discussed here, and therefore, since the mishna teaches with regard to diverse kinds only that one must reduce the additional amount, but not that one is required to remove all the seeds of a different kind, it follows that the same is true in the case of a sale, and the seller should not have to take back all of the impurities. This contradicts Rav Huna’s ruling.

The Gemara deflects the challenge: No, this assumption is not necessarily correct; perhaps the presence of a quarter-kav of seeds of a different kind per se’a with regard to diverse kinds is comparable to a quarter-kav of impurities per se’a with regard to a sale, as discussed here, and both are considered acceptable levels of admixture.

The Gemara asks: If it is so that a quarter-kav of seeds of a different kind per se’a is acceptable, why does the mishna teach that one must reduce the quantity of seeds of a different kind? The Gemara answers: The requirement is a rabbinic decree due to the severity of the prohibition of diverse kinds.

The Gemara challenges this answer: If so,