Bava Batra

AND HE GAVE [HIM] LESS, [EVEN IF ONLY BY] A FRACTION, [AN EQUAL SUM] IS TO BE DEDUCTED [FROM THE PRICE]. [IF] HE GAVE MORE, [EVEN IF ONLY BY] A FRACTION, IT IS TO BE RETURNED [TO HIM]. Thus [it is to be inferred that] had not [the expression 'measured by the rope'] been explicitly used [it would have been] just the same as if [the expression] 'more or less' [had been actually used]. Explain. [however], the concluding clause [which reads]: IF, HOWEVER, HE SAID, 'MORE OR LESS', THE SALE IS VALID EVEN IF HE GAVE [AT THE RATE OF] A QUARTER OF A KAB PER SE'AH LESS OR MORE. Thus [it is to be inferred that] had not [the expression, more or less'] been explicitly used [it would have been] just the same as if [the expression], 'measured by the rope' [had actually been used]! But, [one must conclude, that] nothing may be deduced from this [Mishnah]. Come and hear! [It has been taught: If a man says to another:] 'I sell you a beth kor of arable land', [or] 'I sell you about a beth kor of arable land' [or] 'I sell you [etc] more or less', the sale is valid even if he gave [at the rate of] a quarter [of a Rab] per se'ah less or more. This clearly proves that even when nothing  had been specified it is the same as [if the expression]. 'more or less' [had been used]! That [supplies no proof; for it] is an explanatory statement [implying] the following: In which case is [the expression] a beth kor' regarded as [the expression] 'about a beth kor'? When one said to the other, 'more or less'. R. Ashi demurred to this: If so,  for what purpose is the expression. 'I sell you.' [thrice] repeated? Consequently, the deduction may be made that even when nothing  had been specified it is the same as [if the expression], 'more or less' [had been used]. This proves it. WHAT IS [THE BUYER] TO RETURN TO HIM? — THE MONEY etc. Does this [Mishnah] imply that we are to look after the interests of the seller and not after those of the buyer? Surely it has been taught: [If the land purchased was by] seven kab and a half per kor  less, or by seven kab and a half per kor  more [than the area agreed upon], the sale is valid. [If the surplus is] greater than this, the seller is compelled to sell and the buyer to buy!  — There  we deal with the case where land was first  dear and is now  cheap. [In such a case] the seller is told, 'If you [wish to] give him the land,  give [it] to him at the present cheaper  rate'. But has it not been taught: When he gives it  to him, it must be at the rate at which he had bought of him? — That refers to the case where it was first cheap and is now dear. IF, THEREFORE. THERE WAS A SURPLUS IN THE FIELD OF AN AREA OF NINE KAB, etc. R. Huna said: The [law of] nine kab spoken of  [applies] even in [the case of] a large valley.  But R. Nahman said: Seven kab and a half must be allowed for every Kor,