Commentary for Bava Metzia 5:1
ואיכא למימר כולה למר ואיכא למימר כולה למר אמר סומכוס ממון המוטל בספק חולקין בלא שבועה הכא דליכא דררא דממונא דאיכא למימר דתרוייהו היא לא כ"ש
and where it could be maintained that the whole amount is due solely to that party Symmachus abides by the principle that 'Disputed money of doubtful ownership should be divided without an oath', how much more readily would he abide by that principle in a case where [as in our Mishnah] it can be said that the disputed object belongs to both [and that therefore it should be divided between them without an oath]? It can still be maintained that our Mishnah is in agreement with Symmachus. For the oath imposed upon disputants in our Mishnah is only rabbinical [not Biblical].<span class="x" onmousemove="('comment',' Cf. Shebu. 41a. ');"><sup>1</sup></span>