The Gemara responds: It is Rabbi Meir, as it is taught in a baraita: A minor boy and a minor girl may not perform the ritual through which a yavam frees a yevama of her levirate bonds [ḥalitza], nor may they enter into levirate marriage. In other words, a minor boy whose brother died childless may not perform ḥalitza with his brother’s widow, nor may he enter into levirate marriage with her, even if she is an adult. Likewise, a minor girl whose husband died childless may not perform ḥalitza with her husband’s brother, nor may she enter into levirate marriage with him, even if he is an adult. This is the statement of Rabbi Meir.

The Rabbis said to Rabbi Meir: You have aptly stated that they may not perform ḥalitza, since “man” is written in the passage of the Torah discussing ḥalitza (Deuteronomy 25:7), and we compare a woman to a man, as the aforementioned verse states: “And if the man does not want to take his brother’s wife.” Consequently, neither a minor boy nor a minor girl may perform ḥalitza. But what is the reason that they may not enter into levirate marriage?

Rabbi Meir said to them: A minor boy may not enter into levirate marriage lest, once he is older, he be found to be a sexually underdeveloped man, who is incapable of fathering children. Likewise, a minor girl may not enter into levirate marriage lest, once she is older, she be found to be a sexually underdeveloped woman. And if a sexually underdeveloped boy or girl enters into levirate marriage they will be found to be infringing upon prohibitions against forbidden sexual intercourse where no mitzva applies, as the entire purpose of levirate marriage is to bear children in the name of the deceased.

The Gemara notes: And the Rabbis maintain that one follows the majority of minor boys, and most minor boys are not going to be sexually underdeveloped men; likewise, one follows the majority of minor girls, and most minor girls are not going to be sexually underdeveloped women. In any event, the baraita indicates that Rabbi Meir is concerned for the minority.

The Gemara objects: You can say that you heard that Rabbi Meir is concerned for a common minority, e.g., the minority of sexually underdeveloped men and sexually underdeveloped women. But did you hear him say that one is concerned for an uncommon minority, such as the minority of young girls who menstruate?

The Gemara explains: This minority of young girls who menstruate is also a common minority. As it is taught in a baraita that Rabbi Yosei said: There was an incident in the town of Ein Bul where they immersed a baby girl in a ritual bath before her mother. In other words, the baby girl experienced bleeding so soon after birth that her immersion in a ritual bath occurred before her mother immersed fourteen days after giving birth. And Rabbi Yehuda HaNasi likewise said: There was an incident in Beit She’arim where they immersed a baby girl before her mother. And Rav Yosef said: There was an incident in Pumbedita where they immersed a baby girl before her mother.

The Gemara asks: Granted, the immersions reported by Rabbi Yosei and by Rabbi Yehuda HaNasi are understandable, due to the teruma of Eretz Yisrael, i.e., these incidents occurred in Eretz Yisrael, where the touch of a menstruating girl disqualifies teruma. But in the incident reported by Rav Yosef, which occurred in Babylonia, why do I need to immerse the baby girl? But doesn’t Shmuel say: The teruma of outside of Eretz Yisrael is prohibited only to one whose impurity is due to an emission from his body, e.g., a menstruating woman, or one who experiences a gonorrhea-like discharge [zav]. And this statement applies only with regard to eating teruma, but with regard to touching teruma, there is no prohibition. Since the touch of a menstruating woman does not disqualify teruma outside Eretz Yisrael, why was it necessary to immerse the baby girl in the incident reported by Rav Yosef?

Mar Zutra says: That immersion was necessary only for smearing oil of teruma of outside of Eretz Yisrael. Since smearing is equivalent to eating, it would have been prohibited to smear such oil on the baby girl, were it not for her immersion in a ritual bath. And from where is it derived that smearing is like eating with regard to teruma? As it is taught in a baraita: The verse discussing the prohibition against consuming teruma in a state of ritual impurity states: “And they shall not desecrate the sacred items of the children of Israel, which they set apart for the Lord” (Leviticus 22:15). The verse serves to include in this prohibition one who smears and one who drinks.

Mar Zutra continues: Why do I need a verse to teach that one who drinks teruma in a state of impurity is liable? Isn’t drinking included in the category of eating? Rather, the baraita means that the verse serves to include one who smears, teaching that he is like one who drinks. And if you wish, say that one may derive that smearing is like drinking from here: “And it came into his innards like water, and like oil into his bones” (Psalms 109:18).

As it stands, the halakha that Samaritan girls are considered menstruating women from the time they lie in their cradle is in accordance with the opinion of Rabbi Meir, who is concerned for the minority of young girls who menstruate. The Gemara objects: If so, let us be concerned for the same minority with regard to our girls as well.

The Gemara explains: There is no need to be concerned with regard to our young girls, as we interpret the verse: “And if a woman has an issue” (Leviticus 15:19), and derive from the fact that the verse does not merely state: “A woman,” but: “And if a woman,” that even minor girls are included in the halakhot of a menstruating woman. And consequently, when our girls see menstrual blood, we separate them in the manner of all menstruating women. Therefore, the Sages did not decree with regard to them that all young Jewish girls assume the status of menstruating women. By contrast, with regard to them, Samaritans, who do not interpret the difference between “a woman” and “and if a woman,” when their girls see menstrual blood they do not separate them, and therefore the Sages decreed with regard to them that all Samaritan girls assume the status of menstruating women.

§ The Gemara asks: What is this interpretation of the difference between “a woman” and “and if a woman”? As it is taught in a baraita that from “a woman” I have derived only that the halakhot of menstruation apply to an adult woman. From where do I derive that the halakhot of a menstruating woman also apply to a one-day-old girl? The verse states: “And if a woman.”

The Gemara asks: Apparently, when the verse includes young girls through the word “and” it includes even a one-day-old. But you can raise a contradiction from another baraita, which discusses the verse: “And the woman with whom a man shall lie carnally, they shall both bathe themselves in water, and be impure until the evening” (Leviticus 15:18). From the word “woman” I have derived only that the sexual intercourse of an adult woman is considered intercourse that renders her impure. From where do I derive that the sexual intercourse of a girl aged three years and one day is also classified as intercourse? The verse states: And the woman. Evidently, the word “and” includes only a girl aged three years and one day.

Rava said: These are halakhot transmitted to Moses from Sinai, and the Sages merely supported them with verses. There is therefore no contradiction. The Gemara asks: Which halakha is derived from a verse and which is a halakha transmitted to Moses from Sinai? If we say that the halakha that the status of a menstruating woman may apply to a one-day-old girl is a halakha transmitted to Moses from Sinai, and the halakha that the intercourse of a girl aged three years and one day is considered intercourse is derived from a verse, then one may object: But the verse is written in an unspecified manner; consequently, a one-day-old girl should be included by the verse in the same manner as a three-year-old girl.

Rather, the halakha with regard to the intercourse of a girl aged three years and one day is a halakha transmitted to Moses from Sinai, whereas the halakha with regard to the menstruation of a one-day-old girl is derived from a verse. The Gemara asks: And now that it has been established that the halakha with regard to the intercourse of a three-year-old girl is a halakha transmitted to Moses from Sinai, why do I need a verse?