שעמום ורבי יאשיה האי תחת אישה מאי עביד ליה מיבעי ליה להקיש איש לאשה ואשה לאיש
a mentally ill person [shiamum], whom the court warns on behalf of the husband. The Gemara asks: And according to Rabbi Yoshiya, what does he do with this term “while under her husband”? The Gemara answers: Rabbi Yoshiya requires it in order to compare a man to a woman and a woman to a man, as explained later (27a).
אלא טעמא דכתיבי הני קראי הא לאו הכי הוה אמינא ארוסה שתיא והא כי אתא רבי אחא בר חנינא מדרומא אתא ואייתי מתניתא בידיה (במדבר ה, כ) מבלעדי אישך משקדמה שכיבת בעל לבועל ולא שקדמה שכיבת בועל לבעל
The Gemara asks: But according to both opinions, the reason for the exclusion of a betrothed woman is that these verses are written; if it were not so, I would say that a betrothed woman drinks. But when Rabbi Aḥa bar Ḥanina came from the South, he came and brought the following baraita with him: The verse states: “But if you have gone astray while under your husband, and if you are defiled, and some man has lain with you besides your husband” (Numbers 5:20). This indicates that the halakhot of a sota apply only when sexual intercourse with the husband preceded sexual intercourse with the paramour, and not in a case when sexual intercourse with the paramour preceded intercourse with the husband. In the case of a betrothed woman who committed adultery, intercourse with the paramour preceded intercourse with the betrothed, and this verse excludes her from drinking the bitter water of the sota.
אמר רמי בר חמא משכחת לה כגון שבא עליה ארוס בבית אביה
Rami bar Ḥama said: You find the necessity for an additional exclusion in a case where her betrothed engaged in sexual intercourse with her in her father’s house, i.e., before they were married, and before the sexual intercourse with the paramour.
דכוותה גבי שומרת יבם כגון שבא עליה יבם בבית חמיה הא שומרת יבם קרית לה אשתו מעלייתא היא דהאמר רב קנה לכל
The Gemara questions this explanation: In the corresponding situation with regard to a widow awaiting her yavam, whom Rabbi Yonatan excludes from the sota ritual due to the exclusion from the phrase “while under your husband,” is the necessity for this exclusion due to a case where the yavam engaged in sexual intercourse with her in her father-in-law’s house before the levirate marriage took place? But do you call that woman a widow awaiting her yavam? She is his full-fledged wife, as didn’t Rav say: If a widow awaiting her yavam engaged in sexual intercourse with her yavam, even without the intention of implementing a levirate marriage, he has acquired her as his wife with respect to all aspects of marriage, including the halakhot of a sota.
כשמואל דאמר לא קנה אלא לדברים האמורים בפרשה
The Gemara answers: Rabbi Yonatan’s opinion is in accordance with the opinion of Shmuel, as Shmuel says: A yavam who engages in sexual intercourse with his yevama without intending to consummate the levirate marriage does not acquire her as his wife except with regard to those matters that are stated in the passage in the Torah that deals with levirate marriage, i.e., that he inherits his brother’s estate, and he can free the widow with a bill of divorce without ḥalitza (see Yevamot 56a). He is not considered fully married to the woman, and, according to Rabbi Yonatan, the halakhot of a sota do not apply to her.
אי הכי לימא רב דאמר כרבי יאשיה ושמואל דאמר כרבי יונתן אמר לך רב אנא דאמרי אפילו לרבי יונתן מדאיצטריך קרא למעוטה מכלל דאשתו מעלייתא היא
The Gemara asks: If so, let us say that Rav stated his opinion in accordance with the opinion of Rabbi Yoshiya, and Shmuel stated his opinion in accordance with the opinion of Rabbi Yonatan. The Gemara rejects this interpretation: Rav could have said to you: I state my opinion even according to the opinion of Rabbi Yonatan. Since it was necessary for the verse to exclude a yevama who engaged in sexual intercourse with her yavam from the sota ritual, by inference one may derive that she is his full-fledged wife with regard to all other matters.