The opening sugya establishes that acquisition in Jewish law requires formal mechanisms such as kesef, shtar, or bi'ah, not simply seeing or wanting something.
הָאִשָּׁה נִקְנֵית בְּשָׁלֹשׁ דְּרָכִים, וְקוֹנָה אֶת עַצְמָהּ בִּשְׁתֵּי דְרָכִים. נִקְנֵית בְּכֶסֶף, בִּשְׁטָר, וּבְבִיאָה. בְּכֶסֶף: בֵּית שַׁמַּאי אוֹמְרִים בְּדִינָר וּבְשָׁוֶה דִּינָר, וּבֵית הִלֵּל אוֹמְרִים: בִּפְרוּטָה וּבְשָׁוֶה פְּרוּטָה. וְכַמָּה הִיא פְּרוּטָה – אֶחָד מִשְּׁמֹנָה בָּאִיסָּר הָאִיטַלְקִי. וְכֶסֶף מְנָא לַן – גָּמַר ״קִיחָה״ ״קִיחָה״ מִשְּׂדֵה עֶפְרוֹן. כְּתִיב הָכָא: ״כִּי יִקַּח אִישׁ אִשָּׁה״, וּכְתִיב הָתָם: ״נָתַתִּי כֶּסֶף הַשָּׂדֶה קַח מִמֶּנִּי״,
MISHNA: A woman is acquired by, i.e., becomes betrothed to, a man to be his wife in three ways, and she acquires herself, i.e., she terminates her marriage, in two ways. The mishna elaborates: She is acquired through money, through a document, and through sexual intercourse. With regard to a betrothal through money, there is a dispute between tanna’im: Beit Shammai say that she can be acquired with one dinar or with anything that is worth one dinar. And Beit Hillel say: She can be acquired with one peruta, a small copper coin, or with anything that is worth one peruta. The mishna further clarifies: And how much is the value of one peruta, by the fixed value of silver? The mishna explains that it is one-eighth of the Italian issar, which is a small silver coin. The Gemara continues its explanation: And from where do we derive that betrothal is accomplished by means of giving money? It is derived by means of a verbal analogy between the term expressing taking stated with regard to betrothal and from the term expressing taking with regard to the field of Ephron. How so? It is written here, with regard to marriage: “When a man takes a woman” (Deuteronomy 24:1), and it is written there, concerning Abraham’s purchase of the field of the Cave of Machpelah from Ephron the Hittite: “I will give money for the field; take it from me” (Genesis 23:13). This verbal analogy teaches that just as Ephron’s field was acquired with money, so too, a woman can be acquired with money.