Reference for Bava Metzia 7:13
מאי טעמא הילך נמי כמודה מקצת הטענה דמי
There is, however, another difficulty: How could it be said that our Tanna teaches the same [as R. Hiyya] — are the two cases at all alike? There [viz., in the case of R. Hiyya] the creditor has witnesses [for half the amount claimed], but the debtor has no witnesses [regarding the other half] that he does not owe him it. For if the debtor had witnesses that he did not owe him anything [of the other half claimed], R. Hiyya would not require the debtor to swear [regarding the other half]. But here [in our Mishnah] we are witnesses for the one party as much as for the other [in regard to the right of either to one half of the garment], and yet both have to swear.<span class="x" onmousemove="('comment',' Which would show that the oath is not imposed because of a 'partial admission', but is merely an institution of the Rabbis, as indicated above, and is therefore quite different from the oath imposed by R. Hiyya. ');"><sup>13</sup></span>