Mar Zutra b. Rav Mari

Sixth Generation of Amoraim. He was a colleague of Ravina the Last and debated with him, even though he was much younger than Ravina [פסחים סב:]. Rav Aha Saba was his brother [עיין רב אחא סבא במעשה חלוקת הירושה ].

His Acumen

A case concerning orphans who inherited a promissory note from their father, meaning: a note for a debt owed to their father.

When the orphans came to collect the debt from the note, the debtor produced a 'shover' (receipt), meaning a note stating that the debt had been paid, against their father's promissory note.

Rav Hama said: The orphans cannot collect on the promissory note their father left them, and on the other hand, the note in their possession cannot be torn up.

What was Rav Hama's reasoning? To collect the promissory note is impossible because the debtor produced a shover testifying that the debt was paid! To tear up the note is impossible, because perhaps when the orphans grow up, they will bring proof that the shover is forged! And indeed, a disqualified note is torn up by the court and not left in the hands of its owner! So why are we also concerned that the debtor's shover might be forged and do not tear it up!?

Rav Ahar b. Rava asked Ravina if the Halakha follows Rav Hama?

Ravina told him: In every other instance, the Halakha follows Rav Hama, except for this case! Since the debtor produced a shover testifying that he paid his debt, and we do not consider the witnesses who signed the shover to be liars, therefore, we accept the shover and tear up the promissory note held by the orphans.

However, Mar Zutra b. Rav Mari said: Even in this case, the Halakha follows Rav Hama!

Because if it were truly the case that the shover was authentic and not forged, the debtor should have paid it during their father's lifetime and been rid of this loan. And from the fact that he did not pay the note until after the father's death, we infer that he might have forged the shover!

On the other hand, this is not yet conclusive proof that the note is certainly forged, but only a suspicion, and therefore the orphans do not collect it, but it is also not torn up [בבא בתרא ז:].