Bava Metzia

whilst in R. Tarfon's view too [less than a third] immediately constitutes renunciation, why did they revert [etc.]? R. Tarfon's ruling was [surely] more advantageous to them, for what the Rabbis declared overreaching, R. Tarfon regarded as renunciation! — Do you really think that less than a third, according to R. Tarfon, is identical with less than a sixth on the view of the Rabbis? That is not so: from a sixth to a third, according to R. Tarfon, is as a sixth itself on the view of the Rabbis.  If so, whereat did they rejoice [in the first place]? Hence you may deduce that in the view of the Rabbis, in a case of annulment of the sale, one can always withdraw; they thus rejoiced when R. Tarfon told them that it [an overcharge up to a third] constitutes overreaching.  whilst they reverted [to the ruling of the Rabbis] when he told them [that the time for withdrawing is] all day. For if you should think that in the view of the Rabbis the annulment of the sale  is only within the time that he can shew it to a merchant or to a relative, whereat did they rejoice?  — They rejoiced in respect of a sixth itself. The scholars propounded: In the case of annulment of Sale, on the view of the Rabbis,  can one always retract, or perhaps only within the time necessary to shew [the purchase] to a dealer or a relative? And should you answer, [if only] within the time necessary to shew it to a dealer or a relative, wherein do a sixth and more than a sixth differ? There is a difference: for in the case of a sixth, [only] the defrauded party can retract, whereas in the case of more than a sixth both can retract.  What is the ruling? — Come and hear: THEY REVERTED TO THE RULING OF THE SAGES. Now, if you say that annulment of the sale, on the view of the Rabbis, is only within the time necessary to shew [the purchase] to a dealer or a relative, whereas on R. Tarfon's view it is all day, it is well: on that account they reverted [etc.]  But if you say that in the case of annulment of sale, on the view of the Rabbis, one can always retract, why did they revert [etc.]? Surely R. Tarfon's ruling was more advantageous to them, since he declared overreaching [returnable] the whole day, but no more! — Annulment of sale is rare. Raba said: The law is: In the case of less than a sixth, the sale is valid;  more than a sixth, it is null; [exactly] a sixth, it is valid, but the overcharge is returnable;  and in both cases it is within the time necessary to shew [the purchase] to a merchant or a relative. It has been taught in support of Raba: In the case of overreaching of less than a sixth, the sale is valid; more than a sixth, the sale is null; [exactly] a sixth, he [the defrauded party] retains ownership whilst the overcharge must be refunded: this is R. Nathan's view. R. Judah ha-Nasi said: The vendor has the upper hand;  if he wishes he can say, 'Return me the Purchase,' or, 'Pay up the sum wherein you defrauded me.' And in both cases, it is within the time necessary to shew [the purchase] to a merchant or a relative. UNTIL WHAT TIME IS ONE PERMITTED TO REVOKE [THE SALE] etc. R. Nahman said: This was taught only of the purchaser; but the vendor can always retract.  Shall we say that he is supported [by the Mishnah]? THEY REVERTED TO THE RULING OF THE SAGES. Now, if you agree that the vendor can always retract, it is well: