Bava Batra 62B

בסירוגין, מהו? תיקו.

A third dilemma was also raised before the rabbis: If the seller defined the boundaries of the property he is selling in an alternating fashion, mentioning only some of the fields bordering each side of the field being sold, while omitting others, what is the halakha? No resolution was found for these questions, and these dilemmas should stand unresolved.

מצר לו מצר ראשון ומצר שני ומצר שלישי, ומצר רביעי לא מצר לו ⁠– אמר רב: קנה הכל, חוץ ממצר רביעי. ושמואל אמר: אפילו מצר רביעי. ורב אסי אמר: לא קנה אלא תלם אחד על פני כולה –

§ The Talmud raises a similar dilemma. If, in the bill of sale, the seller delineated for the buyer the field’s first boundary, its second boundary, and its third boundary, but he did not delineate its 4th boundary at all, Rav says: The buyer acquires the entire field, except for the one furrow along which the 4th boundary runs, which is usually differentiated in some way from the field itself. And Shmuel says: The buyer acquires even the furrow along which the 4th boundary runs. And Rav Asi says: He acquires only the width of one furrow along the entire perimeter of the 3 boundaries specified by the seller.

סבר לה כרב, דאמר: שיורי שייר; ומדשייר במצר, שייר נמי בכולהי.

The Talmud explains Rav Asi’s opinion: He holds in accordance with the opinion of Rav, who said that by failing to delineate the 4th boundary, the seller withheld some part of the field, i.e., one furrow, for himself. But Rav Asi takes this further and says that since he withheld some part of the field for himself at the 4th boundary, he withheld also some portion of the entire field, and therefore the buyer acquires only that which is adjacent to the specified boundaries.