If only a married woman can be a sotah, why does a non-spouse have authority to warn her?

Question

Sotah 4:1 explains that certain women do not drink the sotah waters and do not receive the ketubah because they are not yet married and the torah says "she goes astray while married to her husband". This mishna specifically discusses a betrothed woman and a shomeret yavam.

I understand why a woman who is betrothed but not yet married would be subject to warning from her future husband -- he's declared his intentions, and we're just waiting for them to complete the marriage. With a yavam, though, things are uncertain until he acts -- he can either marry the wife of his childless brother who died or he can decline the marriage, and at this point he has done neither. I am surprised to learn that he nonetheless has authority over her as if he were her husband.

Does a yavam in fact have husband-like authority over his maybe-future-wife, and the sotah warning is no different? For example, can he annul her vows or use her property? If so, how do we reconcile that with the quoted text from Bamidbar (5:29)?

Or is this husband-like status specific to the sotah case? If so, how do we learn it?

This question is not about the court's warning per Sotah 4:5; in that case they are acting on behalf of an actual husband.

Answer 1

It is clear from the Gemora 24b that a Yevama before Yibbum (consummation), the Yevama is not at all in her dead husband's brother's authority except:
- She is forbidden to engage in relatonships with anyone else unless Chalitza is performed.
- the brother in-law can warn her as a sotah (Thanks @Monica for mentioning this info) for the future when they are fully married that she cannot be secluded with a man (though if she secludes herself while she is before full marriage as a shomeres Yavam, she does not drink the sotah waters Sotah 25b).

Even after consummation of the brother having fulflled Yibbum, if it was done in her fathers house (i.e there is no chupa - her entering the husbands domain), there is a Machlokes between Rav and Shmuel whether she is a fully married with regards to
1.inheriting her property when she dies, or eating Peiros Nichse milug i.e cut off from her property.
2.metamei(contracting impurity of a dead body) himself inorder to bury her if he's a Cohen
3.hafaras nedorim (anulling her vows).
-Rav holds Yibbum does not require chupa and she is a full wife regarding the aforementioned things as well as inheriting his brother and dvorcing her with a gett, as if Chupa was done in a regular marrage.
-Shmuel holds that she is only his wife with regards to whats written in the parsha, that she is divorced with a Gett rather than Chaitza which is no longer required, and He inherits his dead Brothers property by doing Yibbum but not the three things aforementioned until she enters his chupa.

• So the mishna which excludes Yevama from being a Sotah could be talking according to Shmuel about after she has done Yibbum in her fathers house and she is still not a full wife without chuppah so she cannot become a Sotah. This s explicit in the Gemora.
• Alternatively the Mishna could be talking about before Yibbum where she is not his wife at all and therefore cannot become a Sotah this would be Rav's explanation.

Answer 2

A yabam is not a non-spouse as we can see from the drashot below.

A yabam cannot annul the vows of the yebama

There is a berayta in Yevamot 29b:

שומרת יבם בין יבם אחד בין שני יבמין ר"א אומר יפר ר' יהושע אומר לאחד ולא לשנים דר' עקיבא אומר לא לאחד ולא לשנים

... Rabbi Akiva says, even when there is only one yabam, he cannot make hafarat nedarim for the yebama. The Gemara says that this Berayta is even after maamar.

The Rambam rules as Rabbi Akiva, Hilchot Nedarim 11:23:

שומרת יבם אפילו עשה בה יבמה מאמר ואפילו יבם אחד ליבמה אחת אינו מפר נדרי יבמתו עד שיבא עליה

A yabam cannot use the property of the yebama

See Gemara Yevamot 38a-39a. In 39a, the conclusion (opinion of Rava) of the Gemara is even Bet Shammai, and even after maamar (a kind of Kiddushin given by the yabam before ybum) she is Safek Jesus and cannot use her property.

The yabam can warn the yebama directly, the warning or a shomeret yabam is direct, not by the court. See Gemara 24ab

ורבי יונתן האי איש איש מאי עביד ליה

מיבעי ליה לרבות אשת חרש ואשת שוטה ואשת שעמום

The Gemara asks: And Rabbi Yonatan, who excludes both a betrothed woman and a widow awaiting her yavam from drinking the bitter water, what does he do with this term “any man”? What does it serve to include? The Gemara answers: Rabbi Yonatan requires it in order to include the wife of a deaf-mute and the wife of an imbecile, and the wife of mentally ill person [shiamum], whom the court warns on behalf of the husband.

You see that shomeret yabam isn't included in those whom the court warns on behalf of the husband.

The explanation of the Mishna.

The first interpretation of the gemara (24 a) and the conclusion is that is that our Mishna follows and makes the Drasha of Rabbi Yonatan (regarding the disagreement in berayta if Shomeret Yabam must drink).

(24a) And whose opinion is expressed in the mishna? It is the opinion of Rabbi Yonatan, as it is taught in a baraita with regard to the verse:....(24b) Rabbi Yonatan says: The phrase “while under your husband” excludes a widow awaiting her yavam from drinking the bitter water. Lest one would say that I will exclude a widow awaiting her yavam but I will not exclude a betrothed woman, the verse therefore states: “This is the law of jealousy, when a wife, while under her husband, goes astray, and is defiled” (Numbers 5:29). The term “while under her husband” excludes a betrothed woman from drinking the bitter water.

The Shomeret Yabam has some "stronger properties".

Rabbi Yoshia, who disagrees with Rabbi Yonatan, choices not to exclude her from the drinking because she is more wife than an Arusa, because she doesn't lack Chuppa (for this issue see Yevamot 29b)

Rabbi Yoshiya, holds that the bond with the widow awaiting her yavam is stronger, as she is not lacking entry into the wedding canopy, as her marriage to the yavam is completed through sexual intercourse alone. Rabbi Yoshiya therefore excludes only a betrothed woman from drinking the bitter water.

But she has "weaker properties", the kiddushin don't come from the Yabam himself, the Arusa is stronger, because the kiddushin are from the Arus himself. So, in the first Myut of the drasha he excluded Shomeret Yabam from drinkind, she is less similary to a common wife. From the first Myut (תחת אישך) he excluded Shomeret Yabam, from the second Myut (תחת אישה) he excluded Betrothed woman.

Further Gemara quotes a Drasha Rabbi Aba bar Chanina miDarom saying that there is no "drinking" for a woman who didn't sleep with her "husband" before sleeping with the "Boel". So why do we need the Drashot (תחת אישך, תחת אישה) of Rabbi Yonatan? (I don't explain the side of Rabbi Yoshia here) Gemara says that sometimes the Arus did make a intercourse of znut that is not Nisuyin. In this case we need the Drasha (תחת אישך) to exclude this case from Drinking.

And the Yavam, who makes an intercourse of Znut, despite a intercourse of znut is a valid. , has not all properties of Husband (following Shmuel opinion), so we need the second Drasha (תחת אישה) to exclude him from Drinking.

But Shmuel himself perhaps holds as Rabbi Yoshia (איש איש), and Shomeret Yabam will drink (more accurately Shomeret Yabam who had an intercourse of Znut with the Yabam) because of a Ribuy of Rabbi Yoshia, the ribbuy is a Chiddush that gives to the "shomeret Yabam" the status of wife.

In fine we can assume that the Drasha of of Rabbi Aba bar Chanina miDarom (מבלעדי אישך) is the main choice of the Gemara for a standard betrothed or Shomeret yabam, and the drasha of the Mishna, the drasha of Rabbi Yonatan is auxiliary for particular cases.

This is an explanation almost exhaustive of the Mishna.