2,689. Oaths of Testimony

Hilchos Shevuos 8:14

Let’s say that there were witnesses that someone owed a debt, which the defendant denied with an oath. In such a case, one is liable for an oath of deposit because his denial relieves him of having to pay his debt right away. When the witnesses testify, he will have to pay, thereby rendering his denial ineffective, but it is effective in a case where the witnesses fail to appear, or when their testimony is not accepted, or when they are disqualified. Since the denial is potentially effective, one is liable for an oath of deposit.

Hilchos Shevuos 9:1

Let’s say that a plaintiff insists that witnesses testify about something and that their testimony alone will require the defendant to pay a claim involving moveable goods. The witnesses deny having any testimony and they take an oath to support this claim. In such a case they are liable for an oath of testimony for causing the plaintiff a loss through their denial; this is true regardless of whether they took their oath in court or elsewhere. Similarly, if the plaintiff imposed an oath on the witnesses and they deny having any knowledge, they’re liable even if they don’t take an oath or answer amen to an oath; since they denied having knowledge, they’re liable so long as the plaintiff imposed the oath on them in court.