QUESTION: The Mishnah discusses a case in which a nine year-old boy lives with his Yevamah, and then his nine year-old brother also lives with her. The Tana Kama rules that the woman becomes prohibited to both brothers. Rebbi Shimon rules that she remains permitted to the first Katan.
RASHI asks, why does she remain permitted to the first Katan? When the second Katan lives with her she becomes a Sotah, for she committed adultery with him! Rashi adds that although the adulterer was a Katan, nevertheless his Bi'ah is considered a valid act of Bi'ah and her act is punishable with Misah. Rashi answers that when she lives with the second Katan, she does so b'Shogeg (inadvertently), unaware that the boy is not her husband, or unaware that the act is prohibited. Therefore, she does not become a Sotah and she remains permitted to her husband.
Rashi apparently follows his own opinion as expressed in Kidushin (19a, DH d'mid'Oraisa; see Insights to Yevamos 39:2), that an act of Yibum performed by a nine year-old is considered a valid Yibum mid'Oraisa. Consequently, his act of Yibum creates a bond of Kidushin with the woman, who will become a Sotah if she lives with another man after she does Yibum with the nine year-old.
Nevertheless, Rashi's words are difficult to understand. Rashi writes that "the Bi'ah of a nine year-old is a valid Bi'ah and she is executed for the act of Bi'ah (adultery) with a nine year-old." However, the Gemara in Kidushin (19a) clearly states otherwise. The Gemara there derives from a verse that when a man commits adultery with the wife of a minor, the man and the woman are exempt from punishment. Even Rashi, who maintains that Kidushin d'Oraisa takes effect with a minor, the adulterers are not subject to Misah mid'Oraisa because the verse excludes them from punishment in such a case. (TOSFOS YESHANIM, RABEINU AVRAHAM MIN HA'HAR)
ANSWER: The MAHARSHA and YASHRESH YAKOV explain that Rashi does not mean that in this case, in which the woman is married to a nine year-old, the woman may be executed for committing adultery with another nine year-old. Rather, Rashi means that in a case in which she is married to an adult, she is executed for committing adultery with a nine year-old. (This is similar to what Rashi writes on 51b, DH Bi'as Sheni.) Rashi simply intends to prove from the fact that a woman married to an adult man would be killed for committing adultery with a nine year-old that the Bi'ah of a nine year-old is considered a valid Bi'ah and can prohibit her to her husband.
Accordingly, Rashi here does not necessarily follow his view that the act of Yibum of a nine year-old is effective mid'Oraisa. Even if his act of Yibum is effective only mid'Rabanan and has the status of Ma'amar, Rashi still has a valid question when he asks that she should become prohibited to the minor mid'Rabanan if she lives with another man after the Yibum (as TOSFOS writes on 51b, DH Iy Bi'as Rishon).
Nevertheless, although Rashi's words here do not prove that a minor's act of Yibum is mid'Oraisa, Rashi elsewhere implies that the Yibum of a nine year-old is mid'Oraisa (Kidushin 19a, Nidah 45a, Sanhedrin 55a, DH Kan'ah; see Insights to Yevamos 39:2). The RAMBAN here points out that Rashi later on the page implies that a nine year-old's Yibum is mid'Rabanan. Rashi (DH Harei Zu Peturah) writes that a Katan cannot be Mekadesh a woman with an ordinary act of Kidushin until he develops signs of maturity (two hairs), and yet the Rabanan gave his act of Yibum the status of Ma'amar since she is already Zekukah to him. Rashi implies that the Rabanan instituted a new bond of Kidushin (mid'Rabanan), and did not remove a bond of Kidushin (that existed mid'Oraisa), when they said that a minor's Yibum has the status of Ma'amar (see Yashresh Yakov).
It is likely that Rashi here does not mean that the Rabanan created a new bond through the act of the minor's Yibum. Rather, Rashi means that if the Rabanan invalidated the Yibum d'Oraisa of a nine year-old and ruled that it does not create a real bond because an ordinary act of Kidushin done by a nine year-old is not effective, they should not have given it even the status of Ma'amar. They should have decreed that after the minor lives with his Yevamah, it is as if nothing happened and she remains a Yevamah and is permitted to the other brothers. Rashi addresses that question when he explains that since she is Zekukah to the minor, the Rabanan enacted that there is a bond between them, even though he is a minor.
Rash's question, however, is difficult to understand. Why does Rashi ask that the Rabanan should have instituted that the Yibum of a minor is completely invalid and does not have even the status of Ma'amar? Mid'Oraisa, the woman is married to the minor who did Yibum with her; she is an "Eshes Ish" and needs a Get in order to marry anyone else. She certainly may not do Yibum with any of the other brothers after the minor has done Yibum with her. The minor's Yibum should be at least like Ma'amar with regard to prohibiting her to the other brothers.
The answer is that Rashi means that the Rabanan should have made the minor's act of Yibum like Ma'amar only with regard to prohibiting her from doing Yibum with the other brothers, and not with regard to anything else. There are other ramifications of Ma'amar that should not take effect as a result of the minor's act. For example, the Mishnah here teaches that the Rabanan prohibited the other brothers from doing Yibum with the wife of a minor who died after he did Yibum because of the prohibition of "Eshes Shnei Mesim." If the minor died after he did Yibum, the other brothers may not do Yibum with her because she remains partially Zekukah from the first brother who died (since a full-fledged Yibum mid'Oraisa was not performed with her) and she is also partially Zekukah from the second brother who died (the minor), who lived with her and is considered to have performed Ma'amar with her.
Rashi asks, why should the Yibum of the minor be afforded the status of Ma'amar in this case? A minor cannot marry, and thus when he dies after he takes the Yevamah, she should be considered as though she falls to Yibum (to the other brothers) entirely from one brother (in this case, the first brother, who died before the minor died). Although mid'Oraisa the minor's Yibum is valid and thus the Yevamah may perform Yibum with a third brother because she falls to Yibum entirely from the second brother (the minor), mid'Rabanan she should have the status of one who falls entirely from the first brother (since a minor cannot marry) and the minor's act of Yibum should be ineffective (and thus she should still be permitted to do Yibum with a third brother). Why did the Rabanan institute that the Yibum of the minor has some validity and is judged as Ma'amar, which prohibits the third brother from doing Yibum with her? Rashi answers that since a Zikah-bond already exists between the minor and the Yevamah, the Rabanan allowed some measure of a marriage-bond (Ma'amar) to take effect.
The Gemara relates that Rebbi Yochanan was upset because Rebbi Elazar quoted the teachings of Rebbi Yochanan without attributing them to his name. When one relates teachings in the name of the one who originally taught them, the original source of the teachings merits that his "lips quiver in the grave" and he is considered still alive (Rashi).
Based on the Gemara here, the MAHARSHA (Mahadura Basra) suggests a novel interpretation for why Yakov Avinu was so upset at the news of Yosef's death.
When Yakov Avinu heard that Yosef died, he refused to be comforted. He said, "I will descend to the grave in mourning" -- "Ki Ered El Beni Avel She'olah" (Bereishis 37:35). He did not say "b'Yagon She'olah," as he said when he protested the brothers' desire to take Binyamin to Mitzrayim (Bereishis 42:38), but rather "b'Evel She'olah." Why did he use a different expression?
The Midrash relates that Yakov Avinu taught Yosef everything he learned from Shem and Ever (Bereishis Rabah 84:8, cited by Rashi to Bereishis 37:3). Accordingly, to Yakov Avinu the tragic report that Yosef had died meant that no one would be able to repeat his teachings after his death. This greatly worried him, as he feared that after his death he would "have no mouth, like a mourner (Avel)" (Rashi to Bereishis 25:30) -- his lips would not continue to move with no one alive to repeat his teachings in his name.
When Yakov Avinu refused to be comforted "because (Ki) I will descend to the grave in mourning," he meant, "Although I might be comforted for the loss of my precious son, how can I be comforted for the loss I will endure after I reach the World of Truth, where I will be silent eternally like a mourner?"
When Yakov Avinu was reunited with Yosef, he declared "Amusah ha'Pa'am" -- "Now I can die after having seen your face" (Bereishis 46:30). After he saw that Yosef was still alive, he was no longer afraid to die. He knew that Yosef would teach the Torah he had learned from his father, and thereby cause his father's lips to move in the grave and keep his father alive even after his departure from this world.
When Yosef sent gifts back to his father (after he revealed himself to his brothers and beckoned them to come to Mitzrayim), he selected gifts which would convey to his father that he need not fear eternal silence in the grave. The Gemara in Megilah relates that one of the gifts he sent to Yakov Avinu was aged wine.
The Yerushalmi in Shekalim teaches that the pleasure the deceased experiences when one relates his teachings is comparable to the pleasure of a person "who drinks aged wine; even after he drinks it, the taste remains in his mouth for a long time." When he sent a gift of "Agalos" to his father, Yosef hinted that he did not forget any of his father's teachings; the "Agalos" alluded to the last Halachic discussion which they had together before they were separated (Rashi to Bereishis 45:27). The gift of aged wine indicated that Yosef would repeat Yakov's teachings after Yakov's death, and Yakov's lips would move in the grave, like one who drinks aged wine and continues to have pleasure from the taste after the wine is finished. (See also Insights to Bechoros 31:3.)