Translation:Shulchan Aruch/Choshen Mishpat/229
Paragraph 1- If one sells wheat to another, the buyer must accept ¼ legumes for each seah. If he sells barley, the buyer would accept ¼ chaff for each seah. If he sells lentils, the buyer would accept ¼ of dirt for each seah. If he sells figs, the buyer would accept 10 wormy figs for each 100, and similarly one out of each 10. If one sells other fruits, the buyer would accept ¼ waste for each seah. If any more than the aforementioned amounts were discovered, the seller must sift everything and give the buyer sifted and clear products without any waste. There are those who say that this is only where we do not know that he did not combine them. If it was known that the seller did not combine them, however, the buyer must accept the aforementioned sizes and deduct the surplus. There are those who say that where it is known the seller did not combine them the seller must accept everything. There are those who differentiate and say that this is only where the seller sold fruit without specifying or he said “these nice fruits.” If he said “fruits,” but did not say “nice,” however, the buyer must accept them as is. If he said “nice fruits,” but not “these,” the seller must give fruits that are all nice.
Paragraph 2- All of the foregoing was only said in a place without a custom. In a place that has a custom, however, all rules would follow the custom. There are places that have a custom that all fruits are clean and clear of all other items and all the wine and oil is clear and the seller cannot sell any sediments at all. There are other places that have a custom that even half of the produce can contain sediments or that the fruits have dirt, straw or some other item and be sold as is. Thus, if one were to pick a pebble from another’s threshing floor, he must pay the value of wheat equal to the size of pebble he picked because had he left it there it would have sold as a measurement of wheat. If you would argue that he should just return it, the Rabbis have said one is prohibited from combining anything.