Yevamot 120B

סימן מובהק קא מיפלגי. מר סבר סימן מובהק, ומר סבר לאו סימן מובהק.

is an unambiguous distinguishing mark that they disagree. One Sage, R' Eliezer ben Mahavai, holds that a mole is an unambiguous distinguishing mark and may be relied upon by Torah law. Consequently, if a man’s corpse was identified in this manner, his wife may remarry. And one Sage, the anonymous first tanna, holds that a mole is not an unambiguous distinguishing mark.

ולהך לישנא דאמר רבא סימנין דאורייתא, הא קתני: אף על פי שיש סימנין בגופו ובכליו!

The Talmud asks: According to the first version, that Rava said that distinguishing marks are recognized as valid identification by Torah law, there is a question: Isn’t it taught in the Mishnah: Although there are distinguishing marks on his body and his personal belongings, one may not rely on these as identification, implying that distinguishing marks are not valid identification by Torah law?

גופו ⁠— דארוך וגוץ. כליו ⁠— דחיישינן לשאלה. ואי חיישינן לשאלה, חמור בסימני אוכף היכי מהדרינן?

The Talmud answers: The Mishnah’s intent is that ordinary distinguishing marks on one’s body, which constitute only weak evidence to a person’s identity, e.g., that he was tall or short, are not valid identification. Additionally, one cannot rely upon distinguishing marks on his personal belongings, as we are concerned about borrowing, i.e., perhaps the deceased had borrowed the clothes he was wearing from someone else. The Talmud asks: But if we are concerned about borrowing, then, with regard to returning lost property, how can we return a donkey based solely upon distinguishing marks on the saddle? Why don’t we consider the possibility that the saddle was borrowed?

לא שיילי אינשי אוכפא, דמסקיב ליה לחמרא. מצאו קשור בכיס ובארנקי ובטבעת, היכי מהדרינן?

The Talmud answers: People do not normally borrow a saddle because it bruises the donkey, as the saddle must fit exactly to the donkey’s measurements. The Talmud raises further objections based upon the baraita cited earlier: If he found the lost bill of divorce tied to a purse, or a money bag, or a ring, he may rely upon the distinguishing marks on those items and deliver the bill of divorce to the woman. But how can we return it and not be concerned that these belongings may have been lent to someone else whose bill of divorce is tied to them?