Mishnah Bava Batra 7

¹If a man said to his fellow, “I will sell you a kor’s space of soil”, and it contained crevices ten handbreadths deep or rocks ten handbreadths high, these are not included in the measurement. But if they were less than this they are included. If he said to him, “About a kor’s space of soil”, even if it contained crevices deeper than ten handbreadths or rocks higher than ten handbreadths, they are included in the measurement. ²[If he said, “I will sell you] a kor’s space of soil as measured by a rope”, and he gave him less, the buyer may reduce the price; and if he gave him more, the buyer must give it back. But if he said, “Whether less or more”, even if he gave the buyer a quarter-kab’s space less in every seah’s space, or a quarter kab’s space more in every seah’s space, it becomes his; if [the error] was more than this, a reckoning must be made. What does he (the buyer) give him back? Its value in money; but if the seller wants, he gives him back the land. And why did they say that he could give back its value in money? To strengthen the power of the seller, for if, in a field [containing a kor’s space] there would still have remained to him nine kab’s space, or, in a garden, a half-kab’s space, or according to Rabbi Akiva a quarter-kab’s space, the buyer must give back to him land. And not only must he give back the quarter-kab’s space, but all of the surplus. ³[If he said], “I will sell you [a piece of land] as measured by the rope, whether it is less or more” the condition “whether it is less or more” makes void the condition “as measured by the rope”. [And if he said], “Be it less or more, as measured by the rope”, the condition “as measured by the rope” makes void the condition “be it less or more”, according to Ben Nanas. [If he said, I will sell you a piece of land] by its marks and its boundaries”, and the difference was less than a sixth, the sale stands. If it was as much a sixth the buyer may reduce the price. ⁴If a man said to his fellow, “I will sell you half of the field”, it must be divided between them into portions of equal value, and the buyer takes half of the field [which the other allots to him]. [If he said, “I will sell you] the southern half”, the field must be divided between them into portions of equal value, and the buyer takes the southern half. He accepts responsibility for [providing the ground] for the dividing wall and the large and small ditches. How large is the large ditch? Six handbreadths. And the small ditch? Three handbreadths.