QUESTION: The Gemara cites Ula who says in the name of Rebbi Elazar that if a man betroths a woman by performing Kidushin with a stipulation ("Al Tenai") and then has relations with her, or he performs Kidushin by giving the woman too little money ("Pachos mi'Shaveh Perutah" -- less than a Perutah's worth) and then has relations with her, "everyone agrees" that the Kidushin takes effect and the woman needs a Get. Although the stipulation was not fulfilled, or he gave her less than a Perutah, the Kidushin takes effect because of the Bi'ah, because "Ein Adam Oseh Be'ilaso Be'ilas Z'nus" -- when he has Bi'ah with her, he has intention that his Bi'ah should be l'Shem Kidushin so that it not be a Be'ilas Z'nus.
How can Ula say that "everyone agrees to this," referring to Rav and Shmuel? In the Gemara earlier (73a), Shmuel clearly says that in a case in which one performed Kidushin with a Tenai and then performed Nisu'in without specifying any Tenai, the woman is not considered married and she does not need a Get!
Moreover, Shmuel there says that if a woman -- who was married off by her mother or brothers when she was a Ketanah -- marries someone else after she reaches the age of adulthood, she is considered married to the second man and needs a Get, since she was never married mid'Oraisa to the first husband even though he lived with her after she became an adult. Obviously, Shmuel does not agree that "Ein Adam Oseh Be'ilaso Be'ilas Z'nus"! How, then, could Ula say that "everyone agrees"?
(a) TOSFOS (DH Divrei ha'Kol) explains that according to Ula, what Shmuel means is not that a Be'ilah after the Tenai does not override the Tenai. Rather, the Be'ilah afterwards certainly overrides the Tenai because "Ein Adam Oseh Be'ilaso Be'ilas Z'nus." Shmuel is discussing a case in which the man did Nisu'in without Be'ilah; he did Nisu'in with Chupah alone. That is why the Tenai still remains -- there is no Be'ilah.
If the man did not do Nisu'in with Be'ilah but only with Chupah, why does Rav rule that she needs a Get? The answer is that Rav maintains that by making a Nisu'in with Chupah the husband shows that he is willing to forgo the Tenai (since be obviously plans to have Bi'ah with her during Nisu'in, and he does not want it to be a Be'ilas Z'nus), and therefore the original Kidushin now takes effect.
Why does Shmuel say that the Kidushin of a Ketanah (who later did Mi'un) does not become Kidushin d'Oraisa after the husband lives with her when she reaches adulthood? Tosfos explains (based on the Gemara in Yevamos 110a) that in the case of a Ketanah the Be'ilah is not really a Be'ilas Z'nus because there exists a Kidushin d'Rabanan. That is why Shmuel says that the Be'ilah during adulthood does not effect a Kidushin. However, in a case in which the man was Mekadesh the woman with less than a Perutah and then did Bi'ah with her, the Bi'ah does make a Kidushin, because "Ein Adam Oseh Be'ilaso Be'ilas Z'nus."
(b) The RITVA concludes that there is a printing error in the Gemara and the words "Divrei ha'Kol" ("everyone agrees") should be omitted. Accordingly, Ula expresses only the opinion of Rav and not the opinion of Shmuel.
The practical difference between these two approaches is what happens when the man performs Nisu'in (Chupah) without doing Be'ilah with her. According to Tosfos, the Halachah follows Rav, and Chupah alone without Be'ilah does serve to make them married, because the man forgoes the Tenai when he performs Chupah alone (see Shulchan Aruch EH 38:35). According to the Ritva and other Rishonim, only after Be'ilah does the Kidushin take effect, since "Ein Adam Oseh Be'ilaso Be'ilas Z'nus."
The BEIS SHMUEL (EH 38:59) adds that there is another practical difference. According to Tosfos, it should not be necessary to have witnesses at the time of the Chupah or Be'ilah since the Kidushin was performed earlier with witnesses and now he is just forgoing the Tenai and not making a new Kidushin. (This indeed is how the RAMBAM rules.) According to those who explain that the only reason why the Kidushin takes effect is that he performs a new act of Kidushin (without a Tenai) by doing Be'ilah and "Ein Adam Oseh Be'ilaso Be'ilas Z'nus," there must be witnesses at the time of the Be'ilah in order for the new Kidushin to take effect, because Kidushin takes effect only with witnesses. (This is how the ROSH rules.)
The AVNEI MILU'IM suggests that this practical difference of the Beis Shmuel is not necessarily correct. Rather, even according to Tosfos it could be that witnesses are necessary for the Nisu'in. Although the Kidushin has already been performed and now the husband merely annuls the Tenai (with the Chupah or Be'ilah), nevertheless he annuls the Tenai only in order for the subsequent Be'ilah not to be a Be'ilas Z'nus. To accomplish this, the Chupah must be a proper act of Nisu'in. Nisu'in, the Avnei Milu'im posits, should be considered a "Davar sheb'Ervah" since it affects her with regard to certain Halachos (such as whether her punishment for adultery will be Sekilah or Chenek if she is a Na'arah Me'urasah, and such as becoming Tamei for her if she dies if he is a Kohen). Therefore, just as Kidushin does not take effect without witnesses (Kidushin 66b), the Chupah or Bi'ah does not accomplish Nisu'in when there are no witnesses present, and the subsequent Be'ilah will be a Be'ilas Z'nus in any case. Accordingly, there is no reason to assume that the man forgoes the Tenai with this Chupah or Bi'ah.
(The Avnei Milu'im's assertion that Nisu'in requires the presence of witnesses in order to take effect is disputed by the other Acharonim. Although the TOSFOS RI HA'ZAKEN (Rabeinu Shlomo Min ha'Har) in Kidushin (10b) seems to require the presence of witnesses for Nisu'in to take effect as the Avnei Milu'im writes, the AVNEI NEZER (EH 395) and MARCHESHES (2:1:7) point out that the RAMBAM (Hilchos Ishus 7:23) seems to rule otherwise. The CHELKAS YO'AV (EH 6) proves that the ROSH (Bava Basra 9:16) also does not require witnesses for Nisu'in to take effect. See also OR SAME'ACH, Hilchos Ishus 10:2.)