Related for Bava Batra 211:1
<big><strong>מתני׳</strong></big> בסימניו ובמצריו פחות משתות הגיעו עד שתות ינכה:
<b><i>MISHNAH</i></b>. [IF ONE SAYS, I SELL YOU THIS<span class="x" onmousemove="('comment',' Pointing to a particular field. ');"><sup>1</sup></span> BETH <i>KOR</i>] WITHIN ITS MARKS AND BOUNDARIES', THE SALE IS VALID [IF THE DIFFERENCE<span class="x" onmousemove="('comment',' Between the actual area and that mentioned by the seller. ');"><sup>2</sup></span> IS] LESS THAN A SIXTH;<span class="x" onmousemove="('comment',' Though the mention of beth kor is the same as the mention of 'more or less' (cf. supra 104a), in which case the sale is valid only when the difference is less than one twenty-fourth, or a quarter kab per se'ah, the pointing out of the field and the addition of the stipulation, 'within its marks and boundaries', modify the implication of beth kor, and a greater difference is, consequently, allowed before any deduction can be claimed. While the expression, 'within its marks and boundaries', implies the offer of a specified field whatever be its area, the expression beth kor, used with it, implies an area not too much different in size from that of a beth kor. Hence the law of our Mishnah which limits the allowed difference to a sixth. ');"><sup>3</sup></span>