2,703. When the Testimony of One Witness Creates an Obligation
Hilchos Shevuos 10:9
Similar to the case in the previous halacha, in any scenario where one witness’ testimony will create a financial obligation, the witness denying having information with an oath or the imposition of an oath in court supporting his denial will render him liable for an oath of testimony.
Hilchos Shevuos 10:10
Pursuant to the previous halacha, let’s say that the plaintiff and the defendant each have a history of making false oaths, with the result that they are no longer permitted to make oaths. The plaintiff imposes an oath on a lone witness to testify that the defendant owes him a maneh, and the witness denies having information. In such a case, he’s liable for an oath of testimony because, had he testified, his testimony would have obligated the defendant to pay. The reasons for this will be discussed IY”H in Hilchos To’ein v’Nitan. The same is true in all comparable cases.