יבמות י״אYevamot 11

Mishnah 3ג׳

חָמֵשׁ נָשִׁים שֶׁנִּתְעָרְבוּ וַלְדוֹתֵיהֶן, הִגְדִּילוּ הַתַּעֲרֹבוֹת וְנָשְׂאוּ נָשִׁים וּמֵתוּ, אַרְבָּעָה חוֹלְצִין לְאַחַת, וְאֶחָד מְיַבֵּם אוֹתָהּ. הוּא וּשְׁלשָׁה חוֹלְצִים לְאַחֶרֶת, וְאֶחָד מְיַבֵּם. נִמְצְאוּ אַרְבַּע חֲלִיצוֹת וְיִבּוּם לְכָל אַחַת וְאֶחָת:

[If] the sons of five women [each of whom has an additional son] become mixed up [making their maternity unknown] and they attained majority [remaining] mixed up, and they married wives and died, four [of the surviving sons] undergo Chalitzah from one [Yevama] and one performs Yibum. He [the one who performed Yibum] and three others undergo Chalitzah from a different [second widow] and one performs Yibum. What emerges is four acts of Chalitzah and one act of Yibum for each one [woman].

Mishnah 4ד׳

הָאִשָּׁה שֶׁנִּתְעָרֵב וְלָדָהּ בִּוְלַד כַּלָּתָהּ, הִגְדִּילוּ הַתַּעֲרֹבוֹת, וְנָשְׂאוּ נָשִׁים, וּמֵתוּ, בְּנֵי הַכַּלָּה חוֹלְצִין וְלֹא מְיַבְּמִין, שֶׁהוּא סְפֵק אֵשֶׁת אָחִיו סְפֵק אֵשֶׁת אֲחִי אָבִיו. וּבְנֵי הַזְּקֵנָה, אוֹ חוֹלְצִין אוֹ מְיַבְּמִין, שֶׁהוּא סְפֵק אֵשֶׁת אָחִיו וְאֵשֶׁת בֶּן אָחִיו. מֵתוּ הַכְּשֵׁרִים, בְּנֵי הַתַּעֲרֹבוֹת לִבְנֵי הַזְּקֵנָה חוֹלְצִין וְלֹא מְיַבְּמִין, שֶׁהוּא סְפֵק אֵשֶׁת אָחִיו וְאֵשֶׁת אֲחִי אָבִיו, וּבְנֵי הַכַּלָּה, אֶחָד חוֹלֵץ וְאֶחָד מְיַבֵּם:

[If] the son of a woman becomes mixed up with her daughter-in-law's son [and each woman has other sons] and they attained majority [remaining] mixed up, and they married and died, the [other] sons of the daughter-in-law undergo Chalitzah but do not perform Yibum since there is doubt whether she [each Yevama] is the wife of his brother or the wife of his father's brother. And the [other] sons of the grandmother either undergo Chalitzah or perform Yibum since there is doubt whether she [each Yevama] is the wife of his brother or the wife of his brother's son. [If] the fit [certain] sons die, the mixed up sons undergo Chalitzah from [the wives of] the grandmother's sons but do not perform Yibum since there is doubt whether she [each Yevama] is the wife of his brother or the wife of his father's brother, and [with regard to] the daughter-in-law's sons - one undergoes Chalitzah and one performs Yibum.