Bava Batra — Daf 105b

אלא לעולם זו ולא סבירא ליה והתם טעמא מאי משום דתפיס

הכא נמי הא תפיס

אמר רב הונא אמרי בי רב איסתרא מאה מעי מאה מעי מאה מעי איסתרא איסתרא

מאי קמ"ל תפוס לשון אחרון הא אמרה רב חדא זימנא דאמר רב אי הואי התם הוה יהיבנא כוליה למשכיר

(אי איתמר הא ולא איתמר הא הוה אמינא מיהדר קא הדר ביה אבל הכא) מהו דתימא פרושי קא מפרש קמ"ל:

— But, [it may be replied.] 'this', in fact, [implies that Samuel] is not of the same opinion;  [as, however, his] reason there [for dividing  the monthly rent of the bath house is] because [each one of the parties] is in possession  [of a part of that concerning which they are in dispute], so here  also [the reason why the buyer acquires every se'ah as it is measured out to him is] because it is [then] in his possession. R. Huna said in the name of the school of Rab: [If one says that he would sell an object for] an istira,  a hundred ma'ah, [he is entitled to] a hundred ma'ah. [If he says], 'a hundred ma'ah, an istira'.[he is entitled to] an istira. What does this teach us? That the second expression is to be preferred?  Surely Rab has said it once! For Rab said: Had I been there  I would have given all to the owner.  [Why, then, need Rab say it again?]  — [Since] it might have been said that [the reason Rab would have assigned all to the owner of the bath house] was because [he held that the second expression]  was merely explaining [the first],  therefore,  [it was necessary for Rab] to teach us [the case of the istira].