Jerusalem Talmud Yevamot 3.2

משנה: הָיְתָה אַחַת מֵהֶן אֲסוּרָה עַל הָאֶחָד אִיסּוּר עֶרְוָה אָסוּר בָּהּ וּמוּתָּר בַּאֲחוֹתָהּ וְהַשֵּׁנִי אָסוּר בִּשְׁתֵּיהֶן. אִיסּוּר מִצְוָה אוֹ אִיסּוּר קְדוּשָּׁה חוֹלְצוֹת וְלֹא מִתְיַיבְּמוֹת. הָיְתָה אַחַת מֵהֶן אֲסוּרָה עַל זֶה אִיסּוּר עֶרְוָה וְהַשְּׁנִיָיה אֲסוּרָה עַל זֶה אִיסּוּר עֶרְוָה. הָאֲסוּרָה לָזֶה מוּתֶּרֶת לָזֶה וְהָאֲסוּרָה לָזֶה מוּתֶּרֶת לָזֶה. וְזוֹ הִיא שֶׁאָמְרוּ אֲחוֹתָהּ שֶׁהִיא יְבִמְתָּהּ אוֹ חוֹלֶצֶת אוֹ מִתְיַיבֶּמֶת.

MISHNAH: If one of them was forbidden to one of them by an incest prohibition, that one is forbidden for him but her sister is permitted to him. Both are forbidden to the second [brother]. In case of a commandment prohibition or a holiness prohibition, they have ḥalîṣah but not levirate. If one of [the sisters] was forbidden to that one [brother] by an incest prohition and the other [sister] was forbidden to the [other brother] by an incest prohition, the one who is forbidden for one might be permitted to the other and vice-versa. That is what they said, “Her sister who is her sister-in-law can have ḥalîṣah or be married in levirate.”

הלכה: הָיְתָה אַחַת מֵהֶן אֲסוּרָה כול׳. אָנַס אִשָּׁה וְיָלְדָה בַת וְהָלְכָה וְנִישֵּׂאת לְאָחִיו וְלָהּ אָחוֹת מֵאֵם מֵאִישׁ אַחֵר נְשׂוּאָה לְאָחִיו הַשֵּׁינִי וּמֵת בְּלֹא בָנִים. הֲרֵי זֶה אָסוּר בְּבִתּוֹ וּמוּתָּר בַּאֲחוֹתָהּ. הָדָא הִיא אֲחוֹתָהּ שֶׁהִיא יְבִמְתָּהּ מִתְיַיבֶּמֶת.

HALAKHAH: “If one of them was forbidden,” etc. If a man raped a woman and she had a daughter who married one of his brothers while [the daughter’s] half-sister from another man is married to a second brother: When they died without children, his daughter is forbidden to him but her sister is permitted to him. This exemplifies: “Her sister who is her sister-in-law can be married in levirate.”

הָיְתָה אַחַת מֵהֶן אֲסוּרָה כול׳. אָנַס אִשָּׁה וְיָלְדָה בַת וּבָא אָחִיו וַאֲנָסָהּ וְיָלְדָה בַת וְנָשְׂאוּ שְׁתֵּיהֶן לִשְׁנֵי אַחִים מֵאַב אֲבָל לֹא מֵאֵם. זֶה אָסוּר בְּבִתּוֹ וּמוּתָּר בַּאֲחוֹתָהּ וְזֶה אָסוּר בְּבִתּוֹ וּמוּתָּר בַּאֲחוֹתָהּ. הָדָא הִיא הָאָסוּר לָזֶה מוּתָּר לָזֶה וְהָאָסוּר לָזֶה מוּתָּר לָזֶה.

“If one of them was forbidden,” etc. If one of them raped a woman and she had a daughter, [the woman] in turn was raped by his brother and also had a daughter and both [daughters] married [these]brothers who were paternal but not maternal halfbrothers: Each one of them is forbidden his own daughter but permitted her sister. That exemplifies: The one forbidden for one is permitted to the other and vice-versa.