Jerusalem Talmud Yevamot 2.7

משנה: מִי שֶׁקִּידֵּשׁ אַחַת מִשִִּׁתֵּי אֲחָיוֹת וְאֵינוֹ יוֹדֵעַ אֵיזֶה מֵהֶן קִידֵּשׁ נוֹתֵן גֵט לָזוֹ וְגֵט לָזוֹ. מֵת ולוֹ אָח אֶחָד חוֹלֵץ לִשְׁתֵּיהֶן. הָיוּ לוֹ שְׁנַיִם אֶחָד חוֹלֵץ וְאֶחָד מְיַיבֵּם. קָדְמוּ וְכָנְסוּ אֵין מוֹצִיאִין מִיָּדָם.

MISHNAH: If somebody gave qiddushin to one of two sisters but he does not know to which one of them, he gives a bill of divorce to each. If he died and has one brother, that one has to perform ḥalîṣah with both sisters. If he had two [brothers], one performs ḥalîṣah and one may marry in levirate. If both married without asking, one does not remove [the women] from them.

הלכה: מִי שֶׁקִּידֵּשׁ אַחַת מִשְּׁתֵּי אֲחָיוֹת וְאֵינוֹ יוֹדֵעַ אֵיזֶה מֵהֶן קִידֵּשׁ נוֹתֵן גֵט לָזוֹ וְגֵט לָזוֹ. מֵת ולוֹ אָח אֶחָד חוֹלֵץ לִשְׁתֵּיהֶן. בְּכָל אָתָר אַתְּ אָמַר. אֵין חֲלִיצָה אַחַר חֲלִיצָה. וְהָכָא אַתְּ אָמַר הָכֵין. כָּאן בְּוַודַּאי כָּאן בְּסָפֵק. הָיוּ לוֹ שְׁנַיִם אֶחָד חוֹלֵץ וְאֶחָד מְיַיבֵּם. בְּכָל אָתָר אַתְּ אָמַר. בְּכָל מָקוֹם שֶׁאוֹמְרִים לוֹ. יַיבֵּם. אֵין אוֹמְרִים לוֹ. חֲלוֹץ. וְהָכָא אָמַר אָכֵין. כָּאן בְּוַדַּאי כָּאן בְּסָפֵק. קָדְמוּ וְכָנְסוּ אֵין מוֹצִיאִין מִיָּדָן.

HALAKHAH: “If somebody gave qiddushin to one of two sisters but he does not know to which one of them, he gives a bill of divorce to each. If he died and has one brother, that one has to perform ḥalîṣah with both sisters.” Everywhere else you say “there cannot be ḥalîṣah after ḥalîṣah” but here you say so? There if it is certain, here one is in doubt. “If he had two [brothers], one performs ḥalîṣah and one may marry in levirate.” Everywhere else you say, in any case one asks him to perform the levirate one does not say perform ḥalîṣah; but here you say so? There if it is certain, here one is in doubt. “If both married without asking, one does not remove [the women] from them.”