Sanhedrin 25A

״אימתי״ ו״במה״ אינו אלא לפרש דברי חכמים.

When does this halakha apply, or: In what case is this statement said, he intends only to explain the statement of the Rabbis, not to disagree with them?

רבי יוחנן אמר: ״אימתי״⁠ – לפרש, ו״במה״⁠ – לחלוק. ודכולי עלמא ״אימתי״ לפרש הוא.

Granted, R' Yoḥanan disagrees with R' Yehoshua ben Levi, and says that only the term: When does this halakha apply, indicates that R' Yehuda intends to explain the previous statement of the Rabbis, but the term: In what case is this statement said, indicates that he intends to disagree. But according to everyone, the term when indicates that he intends to explain the previous statement. This is difficult according to Rami bar Ḥama.

גברא אגברא קא רמית? מר סבר: פליגי, ומר סבר: לא פליגי.

The Talmud responds: Are you setting the statement of one man against the statement of another man? One Sage, Rami bar Ḥama, holds that R' Yehuda and the Rabbis disagree even when R' Yehuda employs the term: When does this halakha apply, and one Sage, R' Yehoshua ben Levi, and similarly R' Yoḥanan, holds that they do not disagree.

ולא פליגי? והתניא: בין שיש לו אומנות שלא הוא, בין שאין לו אומנות אלא הוא ⁠– הרי זה פסול.

The Talmud asks: And do they not disagree? But isn’t it taught in a baraita: Whether a dice player has an occupation other than this one, or whether he does not have an occupation other than this one, he is disqualified from bearing witness? This baraita is in accordance with the opinion of Rami bar Ḥama.

ההיא רבי יהודה משום רבי טרפון היא, דתניא: רבי יהודה אומר משום רבי טרפון, לעולם אין אחד מהן נזיר, לפי שלא נתנה נזירות אלא להפלאה.

The Talmud answers: That baraita is not the opinion of the Rabbis in the Mishnah, but rather it is the opinion of R' Yehuda in the name of R' Tarfon. As it is taught in a baraita that R' Yehuda says in the name of R' Tarfon: In the case where two people quarreled and each of them declared that if the other is right he will become a nazirite, actually, neither of them becomes a nazirite, as naziriteship is determined only by explicitness. A vow of naziriteship does not take effect if the individual does not vow clearly and with certitude. Here too, R' Tarfon maintains that one who bets on games played with dice is considered a thief, as one can acquire the money of another legally only if the latter gives it to him with certain and conclusive intent. Since one who plays dice is not certain that he will have to pay the other player, as he considers it likely that he will win, the transaction is an asmakhta and is legally invalid.