Reference for Bava Batra 345:1

ואלא הא דתניא כשם שאין מוציאין שטר חוב זה על זה כך אין מוציאין על אחרים במאי קמיפלגי

Since it was taught, however, 'As they cannot produce a bond of indebtedness against one another so they cannot produce [a bond] against others'<span class="x" onmousemove="('comment',' Because it is possible that one of them lost the bond and the other, who presents it at court, accidentally found it. ');">¹</span> [the question arises]<span class="x" onmousemove="('comment',' Since, as has been said, loss of the bond is not suspected. ');">²</span> wherein [lies the principle of] their disagreement?<span class="x" onmousemove="('comment',' That between the Baraitha and Our Mishnah, from the latter of which it was deduced, supra, that either of the Josephs may produce a bond against others, a deduction with which, since it referred to the case of a particular individual, even Abaye agreed. ');">³</span>

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