BACKGROUND TO THE DAILY DAF
brought to you by Kollel Iyun Hadaf of Yerushalayim
1) [line 3] "KI SIHEYENAH L'ISH SHTEI NASHIM HA'ACHAS AHUVAH VEHA'ACHAS SENU'AH...[LO YUCHAL L'VAKER ES BEN HA'AHUVAH AL PENEI VEN HA'SENU'AH HA'BECHOR...]" - "If a man has two wives, one beloved, and another hated, [and they have born him children, both the beloved and the hated; and if the firstborn son is hers who was hated; Then it shall be, when he makes his sons inherit that which he has, that he may not make the son of the beloved inherit before the son of the hated, who is indeed the firstborn; But he shall acknowledge the son of the hated for the firstborn, by giving him a double portion of all that he has; for he is the beginning of his strength; the right of the firstborn is his.]" (Devarim 21:15-17)
2a) [line 5] AHUVAH B'NISU'EHA - (lit. beloved in her marriage) a woman who is permitted to be married to her husband
b) [line 6] SENU'AH B'NISU'EHA - (lit. hated in her marriage) a woman who is forbidden to be married to her husband because of a Lav
3) [line 25] EIN LAH CHAYIS - she has no recognized ancestry or descent; slaves have no Halachically recognized lineage
4) [line 18] KIDUSHIN SHE'EIN MESURIN L'VI'AH - Kidushin (betrothal) to a woman with whom marital relations will be prohibited
(a) The Amora'im argue with regard to the Halachah of Kidushin "she'Ein Mesurin l'Vi'ah," whether the Kidushin are valid or whether we say that any Kidushin that does not lead to a state where marital relations are permitted are not Kidushin at all and there is no need for a Get (a bill of divorce).
(b) For example, Reuven was Mekadesh one of two sisters (or one of a mother/daughter pair or one of a mother/granddaughter pair) without specifying which woman he was Mekadesh. He handed one Perutah of Kidushin to the two of them simultaneously (e.g. they both appointed the same agent to accept Kidushin for them, and Reuven gave a Perutah to him to be Mekadesh one of them), stating that he wants to be Mekadesh "one of them," without specifying which one. According to the opinion that the Kidushin are valid, one of the two women become married to him, and since it is not known which is the married one both women need a Get mi'Safek (because of the doubt involved). According to the other opinion, no Get is required at all, since Reuven is prohibited from having relations with either of them because of the doubt. (One of them is his wife and the other is the sister -- or daughter or granddaughter -- of his wife; therefore the possibility exists that any one of them is his wife's sister -- or daughter or granddaughter -- who is prohibited to him mid'Oraisa).
(c) This Halachah only applies to Chayavei Kerisus, where the Isur stems from the Kidushin of the first woman, such as a man who is Mekadesh one of two sisters (as described above). It does not apply to a man who is Mekadesh a woman who is prohibited to him because of a Lo Sa'aseh (Chayavei Lavin). Even though he is prohibited from having marital relations with her, the Kidushin is called Kidushin ha'Mesurin l'Vi'ah, since in this case the prohibition against marital relations does not stem from the Kidushin (TOSFOS DH Kidushin).
Index to Background for Maseches Yevamos