Rabban Gamliel says that if the underage sister was not m'Ma'ein, then the older sister who was Nofel for Yibum does not need Chalitzah. Rav Elazar in the Germara offers two possible explanations for Rabban Gamliel's opinion. The first, that Rabban Gamliel holds that even though the original Kidushin of the Ketanah are not valid mi'd'Oraysa, they "hang" (Mitla Talu) until she becomes an adult at which stage they automatically become Kidushin d'Oraysa and therefore the older sister is automatically Patur from the need for Chalitzah. However, we may also explain that Rabban Gamliel holds that the original Kidushin does not become Kidushin d'Oraysa at all automatically and therefore the older sister is only Patur from Chalitzah if the husband instigated a new Kidushin (which would happen if and when he made a Bi'ah after his wife, the younger sister, became of age (a Gedolah)).

Rav told Rebbi Elazar that Rabban Gamliel held like his second explanation. However Rav Sheshes was unhappy with this option since he has a Brayso that said that the Kidushin of the Ketana are Teluyin, which he understood to mean like the first explanation.

Ravin B'reih d'Rav Nachman comes to answer Rav's opinion and contends that the second explanation should not be contradicted from the Brayso. This is because when the Brayso says that Kidushin of a Ketanah are Teluyin, it does not mean that they may turn into Kidushin as Rav Sheshes undersatood. Ravin, however, explains that these words mean to say the opposite, that the Kidushin of the Ketanah cannot become Kidushin d'Oraysa because the Ketanah does not have proper Gemiras Da'as (Lo Samchah Da'atah) because she knows that the Kidushin will only become Kidushin if the husband decides to consumate after she becomes a Gedolah. This being the case, she does not have the required Da'as for Kidushin.

Hu Adif Minai means that he (the husband) is more in control of the Kidushin than me (the wife), because he can terminate the marriage at will. This is a reason why the wife does not have Semichas Da'as at the time of the original Kidushin.

Dov Freedman