Reference for Bava Kamma 210:8
כיצד שורי גנבת והוא אומר לא גנבתי
[has the effect of] excepting a case where there is admission of the substance of the claim, as [where in answer to the plea] 'You have stolen my ox,' the accused says. 'I did not steal it,' but when the plaintiff retorts, 'What then is the reason of its being with you?' the defendant states, 'You sold it to me, you gave it to me as a gift, your father sold it to me, your father gave it to me as a gift, or the ox was running after my cow, or it came of its own accord to me, or I found it straying on the road, or I am a gratuitous bailee regarding it, or I am a paid bailee regarding it, or I am a borrower regarding it,' and after confirming [such a false defence] by an oath he admitted his guilt. But as you might say that he would be liable here, it is therefore stated further: And lieth concerning it,<span class="x" onmousemove="('comment',' Lev. V, 22. ');"><sup>9</sup></span> to except a case like this where there is an admission of the substance of the claim'!<span class="x" onmousemove="('comment',' Why then has Rabbah made a statement to the contrary effect? ');"><sup>10</sup></span>