1) A HALF-SLAVE WHO MARRIES A FREE PERSON
QUESTION: The Gemara discusses two similar cases of partial Kidushin: a case of a man who is half-Eved and half-free who is Mekadesh a Bas Chorin (a free woman), and a case of a Ben Chorin (a free man) who is Mekadesh a woman who is a half-Shifchah and half-free. The question is the same in both cases: does the Kidushin take effect on the free part of the person even though the other part of that person is an Eved or Shifchah?
The Gemara asks whether these cases are comparable to a case of a man who says to a woman that he is Mekadesh half of her (in which case the Kidushin does not take effect), or whether these cases differ from that case because, in that case, the man left over a part which he was not Mekadesh, but in these cases the man was Mekadesh every part that was possible for him to be Mekadesh.
The RAMBAM rules that the Kidushin in the case of a half-Eved, half-free man who is Mekadesh a Bas Chorin is a Safek Kidushin. However, in the case of a Ben Chorin who is Mekadesh a half-Shifchah, half-free woman, the Rambam rules that the Kidushin is completely valid. Why does the Rambam rule differently in each case, if the Gemara here addresses them as based on the same premise? (RAN in Kidushin, 3b of the pages of the Rif)
ANSWER: The AVNEI MILU'IM (44:3) proposes that there is a basic difference between the role of the man, the "Mekadesh," and the role of the woman, the "Mitkadeshes," in the Kidushin process. The role of the man is an active role, while the role of the woman is entirely passive. The specific act of Kidushin is performed by only one party -- the man who is the Mekadesh. The woman is just a recipient of the act of Kidushin, and she is not actively involved in it.
This difference explains why the Rambam rules the way he does in the two apparently similar cases, the case of a half-Eved, half-free man who performs an act of Kidushin, and a half-Shifchah, half-free woman who is merely the recipient of an act of Kidushin. The Rambam assumes that a Kidushin can take effect on half of a person (the half that is free, and not the half that is a Shifchah). However, an act of Kidushin cannot be performed by half of a person. Any act that a person done is per force done by the entire person and not just half of him. Since the Kidushin is done by one who is partly an Eved, it is invalid. (A. KRONENGOLD)
2) AGADAH: GROWTH IN TORAH THROUGH MISTAKES
Rabah bar Rav Huna expounded the verse, "veha'Machshelah ha'Zos Tachas Yadecha" -- "... and let this ruin be under your hand" (Yeshayah 3:6), to be teaching that only through the humiliation that comes about through making mistakes in Torah does a person merit to reach great heights in Torah learning.
The AHAVAS EISAN in Berachos (28a) points out that although the Gemara here maintains that the only way to achieve the truth in Torah learning is by first erring, there are some notable exceptions to this rule.
The Gemara in Sanhedrin (99a) discusses the verse, "Nefesh Amel Amlah Lo" (Mishlei 16:26), and says that when a person toils in Torah to his fullest potential, the Torah, as it were, requests of Hash-m to give over to that person the secrets of the Torah.
Also, the Gemara in Shabbos (63a) relates that "when two Talmidei Chachamim sharpen each other in Halachah, Hash-m makes them successful" in their Torah learning.
The Ahavas Eisan explains that this was the intention of Rebbi Nechunya ben Hakanah in the prayer he authored for one who enters the Beis ha'Midrash to learn: "May it be Your will... that I not stumble in a matter of Halachah and have my friends laugh at me...." Rebbi Nechunya beseeched Hash-m to help him use all of his ability in learning Torah so that he would merit the special gift of being given Torah directly, without having to endure the pain of humiliation that comes from making an error before reaching the truth in Halachah. (A. KRONENGOLD)

43b----------------------------------------43b

3) THE KIDUSHIN OF A HALF-SHIFCHAH WHO WAS THEN FREED
QUESTION: The Gemara discusses a case of a man (Reuven) who was Mekadesh the free part of a half-Shifchah, half-free woman. The woman was then given her full Shichrur and became entirely free. Another man (Shimon) was then Mekadesh her.
The Gemara assumes that one of two things must happen: either the first Kidushin is completely eliminated or now it becomes even stronger and is considered to be completed.
Why does the Gemara not consider the seemingly more logical possibility that the woman remains as she was before she was freed entirely, and she is half-Mekudeshes?
ANSWER: RASHI explains that since the Shifchah received a full Shichrur, she is considered an entirely new person. Therefore, the old Kidushin can no longer work for her. It is as if the Kidushin was done with a different woman.
TOSFOS (DH Gamru) explains that although the Kidushin took effect when she was half-free, after her Shichrur the situation changes since, at the time of the Kidushin, there was no "Shiyur" (no part of her was left without Kidushin that could have received Kidushin). Now that her other half is also free, the Kidushin is viewed as having a "Shiyur" and lacking, since it is now possible for all of her to receive Kidushin. Therefore, one of two things must happen: either the Kidushin becomes entirely invalid or it now spreads to all of her. (A. KRONENGOLD)

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