Reference for Shevuot 64:4

אלא כגון ששניהן חשודין דאמר מר חזרה שבועה למחויב לה ומתוך שאינו יכול לישבע משלם

If you would have come to bear testimony for me, I would have sworn, and taken [the debt]'? Let the witness say to him, 'Who says that you would have sworn? '<span class="x" onmousemove="('comment',' Perhaps you would not have wished to swear, and would not have obtained your money. The witness is therefore merely a possible cause of monetary loss (and does not actually deprive the creditor of his money) ; the Sages (who disagree with R. Eleazar b. R. Simeon) would therefore not hold him liable. Why, then, say that all agree in this case?');">⁴</span>

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