2,691. An Oath of Testimony Regarding a Fine
Hilchos Shevuos 9:4
If someone imposes an oath on witnesses regarding a fine and they deny having information, they are not liable for an oath of testimony. This is because if the defendant were to admit responsibility, he wouldn’t be liable to the fine even if witnesses later come and corroborate his confession. We see from this that witnesses don’t render one liable through their testimony alone; rather, it is their testimony combined with the defendant’s denial that render one liable. Since testimony would be ineffective if the defendant confessed, the witnesses aren’t liable for an oath of testimony if they deny having testimony with an oath.
Hilchos Shevuos 9:5
Let’s say that a plaintiff imposes an oath on witnesses that they testify for him that person X owes him double payment (for simple theft), or four or five times payment (for certain livestock thefts). If the witnesses deny having information, they are liable for an oath of testimony. This is because of the principal, which is the defendant’s financial responsibility, and not because of the extra payments, which are a form of fine. Similarly, if the plaintiff imposes an oath that they testify that person X seduced his daughter and they deny having information, they are liable for an oath of testimony. This is not because of the fine but because of the payments that must be made for embarrassment and damages because if the defendant confesses, he would still have to pay these obligations. The same is true in all comparable cases.