Yerushalmi Yevamot 16:1 ירושלמי יבמות ט״ז:א׳

MISHNAH: If a woman’s husband and her co-wife went overseas and people came and told her “your husband died”, she cannot remarry or perform ḥalîṣah until she has ascertained whether this co-wife was pregnant¹She cannot marry outside the family for the husband might have died childless. She cannot marry the levir for there might be a child born overseas. The Babli, 119a, notes that the expression היא צרתה “this co-wife” implies that she does not have to inquire whether her husband took yet another wife overseas.. If she had a mother-in-law, she does not have to suspect²When she last saw her mother-in-law, her husband was the only son. If the mother-in-law is far away, she does not have to inquire whether in the meantime the latter had another son.. If the latter left pregnant³And now the whereabouts of the mother-in-law are not known; no notice of a brother born to her husband was received., she has to suspect; Rebbi Joshua says, she does not have to suspect⁴The reason is detailed in the Halakhah..

HALAKHAH: “If a woman’s husband and her co-wife went overseas”. Rav asked the elder Rebbi Ḥiyya: Why can she not wait three months and then immediately perform ḥalîṣah? As the case may be, if there was a live birth, ḥalîṣah did not affect her. If there was no live birth, she has ḥalîṣah in her hand!⁷The plain language of the Mishnah implies that the woman is permanently forbidden marriage and levirate until there is proof of her co-wife’s status. This seems to be unreasonable since ḥalîṣah would solve every problem as explained by Rav. He said to him: They taught “three months” only for herself. If so, how long does she have to wait for her co-wife? 9 months.⁸Any ḥalîṣah while her co-wife is pregnant would be invalid; cf. the parallel discussion in Halakhah 4:1, Note 4. After that, could she not immediately perform ḥalîṣah? As the case may be, if there was a live birth, ḥalîṣah did not touch her. If there was no live birth, she has ḥalîṣah in her hand?⁹In the Babli, 119b, this is the tradition of Ze‘iri, student of Rav and Rebbi Joḥanan. There came Rebbi Jehudah in the name of Rebbi Eleazar in the name of the elder Rebbi Ḥiyya¹⁰The name tradition is garbled. There is no mention in any other source of a R. Jehudah younger than R. Eleazar; the double “in the name of” is irregular. In ms. A, the reading is: ר׳ לעזר בשם ר׳ חייה רובה. (?) יהוּדה בן כיני An acceptable reading would be (ר׳) יהוּדה בר בוני ר׳ לעזר בשם ר׳ חייה רובה “Rebbi Jehudah bar Buni, Rebbi Eleazar, in the name of the elder Rebbi Ḥiyya.” In the Babli, 119b, the rule is ascribed to R. Ḥanina, the explanation to Abbai and Ḥanina bar Abin.: That she would not need a proclamation with regard to priesthood¹¹In effect, she is never permitted to marry as long as her situation is not cleared up. The Babli explains that the prohibition is permanent since if it should turn out that the co-wife had a live child overseas, there might be persons who know about the ḥalîṣah ceremony and the marriage to a Cohen but were not informed about the proclamation that the ḥalîṣah was void. These persons would then think that the rabbis do no longer equate a woman after ḥalîṣah with a divorcee. The Babli does not permit the woman to waive her right to marry a Cohen. The position of the Yerushalmi in that last case is not known. Cf. also Chapter 4, Note 5..

The colleagues in the name of Rebbi Joḥanan¹²Text from ms. A.; missing in editio princeps.: The reason of the rabbis: “When [brothers] dwell,” certainly, not in a case of doubt¹³This refers to the statement of the Mishnah that, if the husband had no known brother when he left, the widow does not have to inquire whether his faraway father-in-law had another son..

“If the latter left pregnant, she has to suspect,” since there is one doubt, whether it was a male or a female. A doubt in biblical matters has to be resolved in a restrictive way¹⁶The Babli agrees to this principle, Beṣah 3b.. “Rebbi Joshua says, she does not have to suspect,” since there is a double doubt. There are doubts whether it was a male or a female, and whether it was a live or a still birth¹⁷While the Babli agrees to this principle, Qiddušin 75a, it disagrees in this particular case since the probability of a still birth is rather small. It is argued that if the Yerushalmi reason were true, it could be applied to the case of the co-wife and then the woman left at home would be free to remarry. The Babli explains the position of R. Joshua that the woman was known to be free from levirate when her husband left. Since the probability that the mother-in-law gave birth to a live son is less than 50%, the known prior state remains in force because the probability that it remained in force (that either the mother-in-law had a baby girl who cannot be a levir, or there was a still birth, or a termination of pregnancy) is greater than 50%..