Reference for Bava Batra 124:12

ואמר רבה מצר ארעא דמינה פלגא פלגא מצר ארעא דמינה פסיקא ט' קבין

According to another version, Raba said that the law is that the purchaser acquires the whole, including the fourth boundary. This is the case, however, only if it lies between the two adjoining boundaries, If, however, it does not so lie, he does not acquire it. And even where it does so lie, he acquires it only if there is not on it a clump of date trees, or it has not an area of nine <i>kabs</i>,<span class="x" onmousemove="('comment',' Because here also there is only one weakness in his claim, not two. ');">¹¹</span>

Jastrow