Commentary for Kiddushin 102:2
אביי מתרץ לטעמיה המקדש אשה ובתה או אשה ואחותה כאחת אינן מקודשות הא אחת מאשה ובתה מאשה ואחותה מקודשת
On Raba's view, the first clause is difficult; on Abaye's, the second. Abaye reconciles it according to his opinion IF HE BETROTHS A WOMAN AND HER DAUGHTER OR A WOMAN AND HER SISTER SIMULTANEOUSLY, THEY ARE NOT BETROTHED; but if [he betrothed] one of a woman and her daughter or of a woman and her sister, she is betrothed.
Daf Shevui to Kiddushin
Abaye here solves the entire mishnah such that according to both clauses, kiddushin that cannot be followed by intercourse are valid kiddushin.
Clause 1: If he betroths two women simultaneously that cannot be betrothed consecutively, neither are betrothed. This follows Rabbah’s rule.
Deduction, part 1: If he betroths only one of these women, both are doubtfully betrothed. The kiddushin are essentially valid even though they cannot be followed by intercourse.
Deduction, part 2: If he explicitly says that he is betrothing only the one who is allowed to have sex with him, neither is betrothed. Since he does not know which one he is betrothing, neither of them can have sex with him.
Clause 2: This is exactly what the husband said. The sisters are not married not because “kiddushin that cannot be followed by intercourse are not valid” but because he explicitly stated that he was betrothing only those eligible for intercourse. Thus Abaye has resolved this clause with his opinion.
Clause 1: If he betroths two women simultaneously that cannot be betrothed consecutively, neither are betrothed. This follows Rabbah’s rule.
Deduction, part 1: If he betroths only one of these women, both are doubtfully betrothed. The kiddushin are essentially valid even though they cannot be followed by intercourse.
Deduction, part 2: If he explicitly says that he is betrothing only the one who is allowed to have sex with him, neither is betrothed. Since he does not know which one he is betrothing, neither of them can have sex with him.
Clause 2: This is exactly what the husband said. The sisters are not married not because “kiddushin that cannot be followed by intercourse are not valid” but because he explicitly stated that he was betrothing only those eligible for intercourse. Thus Abaye has resolved this clause with his opinion.
Ask RabbiBookmarkShareCopy