Shevuot 42B

כולהו נמי טענת אחרים והודאת עצמו נינהו!

The Talmud challenges: All other cases where the defendant is required to take an oath due to a partial admission are also cases of a claim of others and his own admission. Yet in the baraita R' Eliezer ben Ya’akov introduces his opinion with the term: There are times, indicating that the case to which he is referring, of one taking an oath on the basis of his own claim, is not the standard case of an oath due to a partial admission.

אלא בדרבה קמיפלגי ⁠– דאמר רבה: מפני מה אמרה תורה מודה מקצת הטענה ישבע? חזקה אין אדם מעיז פניו בפני בעל חובו. והאי ⁠– בכוליה בעי דליכפריה, והאי דלא כפריה ⁠– משום דאינו מעיז פניו בפני בעל חובו;

The Talmud answers: Rather, R' Eliezer ben Ya’akov and the Rabbis disagree with regard to the statement of Rabba, as Rabba says: For what reason did the Torah say that one who admits to a part of the claim must take an oath? It is because there is a presumption that a person does not exhibit insolence by lying in the presence of his creditor, who did him a favor by lending money to him. And this person who denies part of the claim actually wants to deny all of the debt, so as to be exempt, and this fact, i.e., that he does not deny all of it, is because a person does not exhibit insolence in the presence of his creditor.

ובכוליה בעי דלודי ליה, והאי דלא אודי ליה ⁠– אישתמוטי הוא דקא משתמיט מיניה, סבר: עד דהוי לי זוזי ופרענא ליה; ורחמנא אמר רמי שבועה עילויה, כי היכי דלודי ליה בכוליה.

Rabba continues: And in order not to exhibit insolence, he wants to admit to the creditor with regard to all of the debt; and this fact, i.e., that he did not admit the entire debt to him, is because he may be temporarily avoiding paying him. He rationalizes doing so by saying to himself: I am avoiding him only until the time that I have enough money, and then I will repay him. And therefore, God says in the Torah: Impose an oath on him in order to induce the debtor to admit the entire debt to him.