How fragmented must a yad be before is not a vow? TB Nedarim 4-5

In the context of vows a yad (יָד) is a fragmented sentence (Sefaria.org translates yad as intimation-gg) that are like vows. Starting on yesterday’s daf and continuing on today’s daf TB Nedarim 5 presents the disagreement between Shmuel and a couple of baraitot concerning how much does a person have to say for the yad to be a vow. A yad falls into two categories. The first category is unambiguous yadayim (יָדַיִם מוֹכִיחוֹת). The second category are ambiguous yadayim (יָדַיִם שֶׁאֵין מוֹכִיחוֹת), meaning the fragmented sentence can be equally interpreted in different ways.

Shmuel holds that ambiguous yadayim are not yadayim at all; consequently, the person making the yad has to say “With regard to one who says to another: I am avowed from you, or: I am separated from you, or: I am distanced from you, and he then says: That which I eat of yours, or: That which I taste of yours, even though he did not explicitly state that he is taking a vow or specify the nature of the vow, the object of his vow is nevertheless forbidden. His intention is understood based on his incomplete statement, known as an intimation of a vow, and his vow therefore takes effect.” (Sefaria.org translation) While the baraitot hold that “one who says to another: I am avowed from you, or: I am separated from you, or: I am distanced from you” is sufficient for a vow.

The Gemara explains how Shmuel could understand the phrases “I am avowed from you, or: I am separated from you, or: I am distanced from you” in a way that would not be a vow. “If he said simply: I am avowed from you, that statement does not indicate that he said he is prohibited from eating an item belonging to his fellow. What is the reason for this? The statement: I am avowed from you, indicates: I am not speaking with you. Similarly, the statement: I am separated from you, indicates: I am not doing business with you. The statement: I am distanced from you, indicates that I will not stand within four cubits of you.” (Sefaria.org translation)

You may ask how Shmuel, an amora, can argue against tannaitic sources. The Gemara provides the answer. He sides with the tanna Rabbi Yehuda. “Rabbi Yehuda, who said: Ambiguous intimations (יָדַיִם) are not intimations.” (Sefaria.org translation)

The halakha follows the Gemara’s understanding of Shmuel.  Rambam, Mishneh Torah, Vows 1:23

הָאוֹמֵר לַחֲבֵרוֹ מֻדָּר אֲנִי מִמְּךָ מַשְׁמַע דָּבָר זֶה שֶׁלֹּא יְדַבֵּר עִמּוֹ. מֻפְרָשׁ אֲנִי מִמְּךָ מַשְׁמָעוֹ שֶׁלֹּא יִשָּׂא וְיִתֵּן עִמּוֹ. מְרֻחָק אֲנִי מִמְּךָ מַשְׁמָעוֹ שֶׁלֹּא יֵשֵׁב בְּאַרְבַּע אַמּוֹתָיו. וְכֵן אִם אָמַר לוֹ מְנֻדֶּה אֲנִי לְךָ אוֹ מְשַׁמַּתְנָא מִמְּךָ. אֲבָל אִם אָמַר לוֹ מֻדָּר אֲנִי מִמְּךָ שֶׁלֹּא אֹכַל לְךָ. אוֹ מֻפְרָשׁ אֲנִי מִמְּךָ שֶׁלֹּא אֹכַל לְךָ אוֹ מְרֻחָק אֲנִי מִמְּךָ שֶׁלֹּא אֹכַל לְךָ הֲרֵי זֶה אָסוּר לֶאֱכל. וְאִם אָכַל כְּזַיִת מִכָּל נְכָסָיו לוֹקֶה מִשּׁוּם (במדבר ל ג) "לֹא יַחֵל דְּבָרוֹ":

When a person tells a colleague, "I am taking a vow from you," his statement implies that he will not speak with him.62 "I am separate from you" implies that he will not do business with him. "I am distant from you" implies that he will not sit within four cubits of him. That same implication is conveyed by telling him: "I am ostracized from you" or "I am banned from you."63

 

If, however, says "I am taking a vow from you in that I will not eat from your [property]," "I am separate from you in that I will not eat from your [property]," or "I am distant from you in that I will not eat from your [property]," he is forbidden to eat from his [property].64 If he eats an olive-sized portion [of food] from any of his property, he is liable for lashes for [violating the prohibition]: "He shall not desecrate his word." (Sefaria.org translation)