Bava Kamma 40B

אם תם ⁠– הוה מודינא, ומפטרינא!

If the ox was innocuous, I would have admitted my liability and would thereby have been exempt. A fine is imposed only as result of the testimony of two witnesses; if the offender admits his liability, no fine is imposed. Therefore, since the liability to pay half the cost of the damage for the act of an innocuous ox is a fine, the borrower could have rendered himself exempt from liability through admission.

ואפילו למאן דאמר פלגא נזקא ממונא, נימא ליה: אי תם הוא ⁠– הוה מעריקנא ליה לאגמא!

And even according to the one who says that payment of half the damage is considered monetary restitution, not a fine, and therefore his admission would not have rendered himself exempt from liability, let the borrower say to him: If the ox was innocuous, I would have smuggled it out to the marsh [agma] so that the injured party would not find it in my possession. He would then be unable to collect damages from me, since he can collect payment only from the proceeds of the sale of the ox. By contrast, compensation for damage caused by a forewarned ox can be collected from all of the owner’s property, and the borrower had no way of rendering himself exempt from liability. Therefore, it is unclear why the borrower is liable to pay half the cost of the damage.

אלא הכא במאי עסקינן ⁠– כגון דאקדים בי דינא, ותפסיה.

The Talmud answers: Rather, here we are dealing with a case where the court seized the ox first, before the borrower had the chance to admit his liability or to smuggle the ox to the marsh. Therefore, the borrower cannot claim that he would have been able to render himself exempt from liability.