Halacha
הלכה א
מִי שֶׁקִּדֵּשׁ אַחַת מִשְּׁתֵּי אֲחָיוֹת וְאֵין יָדוּעַ אֵי זֶה מֵהֶן קִדֵּשׁ וּמֵת וְלוֹ אָח. אֶחָד חוֹלֵץ לִשְׁתֵּיהֶן כְּדֵי לְהַתִּירָן לַאֲחֵרִים. הָיוּ לוֹ שְׁנֵי אַחִין אֶחָד חוֹלֵץ לְאַחַת מֵהֶן בַּתְּחִלָּה וְהַשֵּׁנִי מְיַבֵּם לַשְּׁנִיָּה עַל כָּל פָּנִים. אִם זוֹ הִיא שֶׁקִּדֵּשׁ אָחִיו הֲרֵי יִבֵּם אוֹתָהּ. וְאִם אֵינָהּ אֵשֶׁת אָחִיו הֲרֵי נָשָׂא אִשָּׁה מִשְּׁאָר הַנָּשִׁים וַאֲחוֹתָהּ שֶׁהָיְתָה אֵשֶׁת אָחִיו כְּבָר נֶחְלְצָה. אֲבָל לֹא יְיַבֵּם הָאַחַת תְּחִלָּה שֶׁמָּא הָאַחֶרֶת הִיא אֵשֶׁת אָחִיו וְנִמְצָא שֶׁנָּשָׂא קְרוֹבַת זְקוּקָתוֹ. קָדְמוּ שְׁנֵי הָאַחִים וְכָנְסוּ שְׁתֵּי הַיְבָמוֹת אֵין מוֹצִיאִין אוֹתָן מִיָּדָן:
כסף משנה
1.
[The following rules apply when a man] consecrates one of two sisters, but does not know which one he has consecrated1Note the Shulchan Aruch (Even HaEzer 176:1), which states that this law applies even if the deceased brother never knew which sister he consecrated, and thus it was forbidden for him to consummate the marriage. Nevertheless, chalitzah is required. and then dies [childless]. If he has one brother, [the brother] should perform chalitzah with both of them to enable them to marry other men.If he has two brothers, one of them should first perform chalitzah with one of [the sisters], and the other should perform yibbum with the other one2This and the laws that follow are based on the Rambam's conception (see Chapter 1, Halachah 2) that when possible, the mitzvah of yibbum takes precedence over the mitzvah of chalitzah. According to the Ashkenazic authorities, different laws apply. [because of the following rationale]: If this was the woman consecrated by his brother, he performed yibbum with her. If she is not his brother's wife, he has married a woman [permitted to him] like any other woman, and chalitzah has already been performed for her sister, his brother's wife.
One should not perform yibbum with one of the women first, for perhaps the other was in fact his brother's wife, and he will have married a relative of the woman who is obligated [to perform yibbum with] him.3This is a Rabbinic prohibition. If, without asking Rabbinic advice,4Our translation is based on the Shulchan Aruch (loc. cit.). If a Rabbinical opinion was sought and then ignored, the yevamim are required to divorce their wives. each of the brothers married one of the sisters, they are not forced to dissolve the marriage.5Although one of them surely violated a Rabbinic prohibition, since we are unable to determine which of them it was, they are both allowed to remain married. This follows the principle sefeka d'rabbanan l'kula, "When a doubt arises regarding the violation of a Rabbinic prohibition, the more lenient perspective is followed."
הלכה ב
שְׁנַיִם שֶׁקִּדְּשׁוּ שְׁתֵּי אֲחָיוֹת. זֶה אֵינוֹ יוֹדֵעַ אֵי זוֹ קִדֵּשׁ וְזֶה אֵינוֹ יוֹדֵעַ אֵי זוֹ קִדֵּשׁ. וּמֵתוּ שְׁנֵיהֶן. לָזֶה אָח וְלָזֶה אָח. זֶה חוֹלֵץ לִשְׁתֵּיהֶן וְזֶה חוֹלֵץ לִשְׁתֵּיהֶן. לָזֶה אָח אֶחָד וְלָזֶה שְׁנַיִם. הַיְחִידִי חוֹלֵץ לִשְׁתֵּיהֶן בַּתְּחִלָּה וְהַשְּׁנַיִם אֶחָד חוֹלֵץ רִאשׁוֹנָה וְהַשֵּׁנִי מְיַבֵּם. וְאִם קָדְמוּ וְכָנְסוּ אֵין מוֹצִיאִין מִיָּדָן. וַאֲפִלּוּ הָיוּ כֹּהֲנִים שֶׁהַחֲלִיצָה שֶׁחָלַץ הַיְחִידִי מִסָּפֵק חָלַץ וְהַחֲלוּצָה אֲסוּרָה לְכֹהֵן מִדִּבְרֵי סוֹפְרִים וּבִסְפֵק חֲלוּצָה לֹא גָּזְרוּ:
כסף משנה
2.
[The following rule applies when] two [men who are not related,] each having one brother, consecrate two sisters, neither of the men knows which [sister] he consecrated, and they both die [childless]. Each [brother] should perform chalitzah with each of the sisters.6Even after the brother of one of the deceased performs chalitzah with both women, the brother of the other deceased may not perform yibbum with one of the sisters, because she is the sister of the woman with whom he is obligated to perform yibbum (or with whom he performed chalitzah).[In the above situation, if] one of the deceased has one brother, and the other has two brothers, the one brother should perform chalitzah with both women first, and then one of the two brothers should perform chalitzah [with one woman] first, and the second one [should perform yibbum with the other].7This and the clause that follows are restatements of the principles mentioned in the previous halachah. If, [without asking Rabbinic advice, each of the brothers] married [one of the sisters], they are not forced to dissolve the marriage.
[The above applies] even if the brothers were priests. [Although] there is a Rabbinic prohibition against a priest marrying a woman who performed chalitzah, the chalitzah performed by this woman was performed because of doubt, and [our Sages] did not enforce a decree with regard to a chalitzah performed because of doubt.8In most instances, if there is a doubt with regard to a Rabbinic prohibition, one may a priori perform the act in question. In this instance, it is only after the fact that yibbum is permitted. The reason for this stringency is that chalitzah is performed in public, and when people see that a woman who performed chalitzah married a priest, they may not appreciate the details of the particular instance and come to the false conclusion that there is no prohibition in doing so (Maggid Mishneh).
הלכה ג
הָיוּ לָזֶה שְׁנֵי אַחִין וְלָזֶה שְׁנֵי אַחִין. אָחִיו שֶׁל זֶה חוֹלֵץ לְאַחַת וְאָחִיו שֶׁל זֶה חוֹלֵץ לָאַחֶרֶת. וְאַחַר כָּךְ הָאָח הַשֵּׁנִי שֶׁל זֶה מְיַבֵּם חֲלוּצָתוֹ שֶׁל זֶה. וְהָאָח הַשֵּׁנִי שֶׁל זֶה מְיַבֵּם חֲלוּצָתוֹ שֶׁל זֶה. קָדְמוּ שְׁנֵיהֶן וְחָלְצוּ לִשְׁתֵּיהֶן לֹא יְיַבְּמוּ שְׁנֵי הָאַחִין הָאֲחֵרִים. אֶלָּא אֶחָד חוֹלֵץ בַּתְּחִלָּה וְאָחִיו מְיַבֵּם לַשְּׁנִיָּה. וְאִם קָדְמוּ וְכָנְסוּ אֵין מוֹצִיאִין מִיָּדָן:
כסף משנה
3.
In the above instance,] if both of the deceased had two brothers, one of one pair of brothers should perform chalitzah with one of the sisters, and one of the other pair of brothers should perform chalitzah with the other sister. Afterwards, the other brother from the first pair should perform yibbum with the sister with whom the brother from the other pair performed chalitzah, and the other brother from the second pair should perform yibbum with the sister with whom the brother from the first pair performed chalitzah.9This also is basically a restatement of the principles mentioned in the first halachah.If both [brothers from one pair each] performed chalitzah with [one of the sisters] first, the brothers from the other pair should not both perform yibbum.10Although the woman may be his yevamah, she may also be the sister of the woman with whom he is obligated to perform yibbum, and whom he is therefore forbidden to marry. Instead, one should perform chalitzah [with one of the sisters] first, and then his brother should perform yibbum with the other. If, without asking Rabbinic advice, each of the brothers married one of the sisters, they are not forced to dissolve the marriage.
הלכה ד
הָאִשָּׁה שֶׁהָיוּ לָהּ בָּנִים וְהָיוּ לְכַלָּתָהּ בָּנִים וְנִתְעַבְּרָה הָאִשָּׁה וְנִתְעַבְּרָה כַּלָּתָהּ וְיָלְדוּ שְׁתֵּיהֶן בְּמַחֲבוֹאָה אַחַת וְנִתְעָרְבוּ שְׁנֵי הַיְלָדִים וְהִגְדִּילוּ הַתַּעֲרוֹבוֹת וְנָשְׂאוּ נָשִׁים וּמֵתוּ. כֵּיצַד הֵן נִתָּרוֹת. בְּנֵי הַכַּלָּה חוֹלְצִין לִשְׁתֵּיהֶן תְּחִלָּה וְלֹא מְיַבְּמִין שֶׁכָּל אַחַת מֵהֶן סָפֵק שֶׁהִיא אֵשֶׁת אָחִיו וְתִהְיֶה מֻתֶּרֶת לוֹ, סָפֵק שֶׁהִיא אֵשֶׁת אֲחִי אָבִיו וְהִיא עֶרְוָה עָלָיו. אֲבָל בְּנֵי הַזְּקֵנָה אוֹ חוֹלְצִין אוֹ מְיַבְּמִין. שֶׁאִם הִיא זוֹ אֵשֶׁת אָחִיו הֲרֵי יִבְּמָהּ. וְאִם הִיא אֵשֶׁת בֶּן אָחִיו מֻתֶּרֶת לְהִנָּשֵׂא לוֹ שֶׁכְּבָר נֶחְלְצָה:
כסף משנה
4.
[The following situation gives rise to several halachic questions:] A woman had sons, and one of her daughters-in-law also had sons. Both the woman and her daughter-in-law became pregnant and they gave birth in the same hiding place. [There was a disturbance] and the identity of the two children became confused [and it was not known who was the son of the mother, and who, the son of the daughter-in-law].The two sons grew up and married and then died [childless]. How are their wives freed to marry others?11For it is unknown who should perform either yibbum or chalitzah, the sons of the mother or the sons of the daughter-in-law.
First, [one of] the sons of the daughter-in-law should perform chalitzah with [both women]; he should not perform yibbum. [The rationale is that] there is a doubt regarding the identity of each of the women. It is possible that she is the wife of his brother and thus permitted to him, but it is also possible that she is the wife of his father's brother and thus forbidden to him as an ervah.
Afterwards,] the sons of the elder woman may perform either chalitzah or yibbum. [With regard to each of the women, the same question applies:] If she is his brother's wife, he is performing yibbum. And if she is the wife of his brother's son, she is permitted to marry him, because she has already performed chalitzah.
הלכה ה
מֵתוּ הַבָּנִים הַיְדוּעִים שֶׁל זְקֵנָה וְשֶׁל כַּלָּתָהּ וַהֲרֵי בְּנֵי הַתַּעֲרוֹבוֹת קַיָּמִין. בְּנֵי הַתַּעֲרוֹבוֹת לִנְשֵׁי בְּנֵי הַזְּקֵנָה חוֹלְצִין וְלֹא מְיַבְּמִין שֶׁהִיא סְפֵק אֵשֶׁת אֲחִי אָבִיו שֶׁהִיא עֶרְוָה עָלָיו, סְפֵק אֵשֶׁת אָחִיו שֶׁהִיא מֻתֶּרֶת לְיַבְּמָהּ. וְלִנְשֵׁי בְּנֵי הַכַּלָּה אֶחָד חוֹלֵץ בַּתְּחִלָּה וְאֶחָד מְיַבֵּם עַל כָּל פָּנִים. אִם בֶּן הַכַּלָּה הוּא שֶׁחָלַץ תְּחִלָּה הֲרֵי חָלַץ אֵשֶׁת אָחִיו וְהַשֵּׁנִי מִן הַתַּעֲרוֹבוֹת הוּא בֶּן הַזְּקֵנָה וּמֻתָּר לוֹ לִשָּׂא אֵשֶׁת בֶּן אָחִיו אַחַר שֶׁנֶּחְלְצָה מִיבָמָהּ. וְאִם זֶה שֶׁחָלַץ תְּחִלָּה הוּא בֶּן הַזְּקֵנָה הֲרֵי חָלַץ לְאֵשֶׁת בֶּן אָחִיו וְלֹא עָשָׂה כְּלוּם וְהַשֵּׁנִי מִן הַתַּעֲרוֹבוֹת הוּא בֶּן הַכַּלָּה וַהֲרֵי יִבֵּם אֵשֶׁת אָחִיו:
כסף משנה
5.
[In the above situation, the following procedure should be carried out if] the sons of the elder woman and her daughter-in-law whose identities had been established died [childless], and the two sons whose identities were confused were alive.The sons whose identities were confused should perform chalitzah with the wives of the elder woman's sons; they may not perform yibbum. [The rationale is that] there is a doubt whether [each woman] is the wife of his father's brother and thus forbidden to him as an ervah, or the wife of his brother and thus permitted to her yavam.
With regard to the wives of the sons of the daughter-in-law: First, one should perform chalitzah and the other should perform yibbum. The rationale is that if the son of the daughter-in-law was the one who performed chalitzah first, he performed chalitzah with his brother's wife. The second one of those whose identities were confused was the son of the elder woman. He is permitted to marry the wife of his brother's son after her yavam performed chalitzah with her.
If it was the son of the elder woman who performed chalitzah first, he performed chalitzah with the wife of his brother's son, and his deed is of no consequence. The second one of those whose identities were confused was the son of the daughter-in-law, and he performed yibbum with his brother's wife.
הלכה ו
מִי שֶׁלֹּא שָׁהֲתָה אַחַר מִיתַת בַּעְלָהּ שְׁלֹשָׁה חֳדָשִׁים וְנִשֵּׂאת וְיָלְדָה וְאֵין יָדוּעַ אִם בֶּן תִּשְׁעָה לָרִאשׁוֹן אִם בֶּן שִׁבְעָה לָאַחֲרוֹן. וְהָיוּ לָהּ בָּנִים מִן הָרִאשׁוֹן וּמִן הַשֵּׁנִי. אִם מֵת זֶה הַבֵּן הַסָּפֵק. בְּנֵי הָרִאשׁוֹן וּבְנֵי הַשֵּׁנִי חוֹלְצִין לְאִשְׁתּוֹ וְלֹא מְיַבְּמִין. שֶׁכָּל אֶחָד מֵהֶן שֶׁיָּבוֹא לְיַבֵּם שֶׁמָּא אֵינוֹ אָחִיו מֵאָבִיו וַהֲרֵי הוּא אָחִיו מֵאִמּוֹ בְּוַדַּאי וְאֵשֶׁת אָחִיו מֵאִמּוֹ אֲסוּרָה עָלָיו לְעוֹלָם מִשּׁוּם עֶרְוָה. וְכֵן זֶה הַבֵּן הַסָּפֵק חוֹלֵץ לִנְשׁוֹתֵיהֶן וְלֹא מְיַבֵּם:
כסף משנה
6.
[The following rules apply with regard to] a woman who did not wait three months after the death of her husband [before] remarrying].12See Hilchot Gerushin 11:18, which states that a woman should wait three months after her husband's death, so that it will be possible to determine who fathered her child. She remarried and gave birth, and it is not known whether the child she bore was fathered by the first husband and was born after a full term pregnancy, or whether it was fathered by the second husband and was born after a seven-month pregnancy.13For example, the woman remarried two months after her first husband's death and gave birth seven months after her second marriage. Thus, it is unknown whether her child was fathered by her first husband or her second.If the woman bore other children to both her first and second husbands, and then this son whose [father's identity] is in doubt dies [childless], both the sons of the first husband and the sons of the second husband should perform chalitzah with [the deceased's] wife, but they should not perform yibbum.
[The rationale is that the obligation for] each of them to perform yibbum is doubtful, for perhaps he is not the paternal brother [of the deceased]. And he is definitely a maternal brother [of the deceased], and the wife of a maternal brother is always forbidden as an ervah. For this same [reason], the son whose [father's identity] is in doubt should perform chalitzah with any of the wives of [his other brothers], but should not perform yibbum.
הלכה ז
הָיָה בֵּן לָרִאשׁוֹן וּבֵן לַשֵּׁנִי שֶׁלֹּא מֵאִשָּׁה זוֹ שֶׁנִּשֵּׂאת בְּתוֹךְ זְמַן וּמֵת אֶחָד מֵהֶן. הֲרֵי הַבֵּן הַסָּפֵק חוֹלֵץ לְאֵשֶׁת זֶה שֶׁמֵּת אוֹ מְיַבֵּם. שֶׁאִם אָחִיו מֵאָבִיו הוּא הֲרֵי יִבֵּם אֶת אִשְׁתּוֹ וְאִם אֵינוֹ אָחִיו מֵאָבִיו הֲרֵי אֵין בֵּינֵיהֶן אַחֲוָה כְּלָל לְפִיכָךְ מֻתָּר לוֹ לִשָּׂא אֶת אִשְׁתּוֹ:
כסף משנה
7.
If both this woman's first and second husbands had fathered another son14The law that follows applies when the woman's husbands have each fathered only one other son with another wife. with another wife, and one of these other sons died [childless], the son whose [father's identity] is in doubt may perform either chalitzah or yibbum with the wife of the deceased. [The rationale is] that if [the deceased] was his paternal brother, then he has performed yibbum. And if he was not his paternal brother, then they have no family connection at all, and he is permitted to marry [the deceased's] wife.הלכה ח
מֵת הַבֵּן הַסָּפֵק אֶחָד מִשְּׁנֵי הַבָּנִים הַוַּדָּאִין חוֹלֵץ לְאִשְׁתּוֹ תְּחִלָּה וְהַשֵּׁנִי מְיַבֵּם עַל כָּל פָּנִים. אִם אָחִיו הוּא הֲרֵי יִבֵּם אֶת אִשְׁתּוֹ. וְאִם אֵינוֹ אָחִיו וְהוּא בֶּן הָאָב הָאַחֵר הֲרֵי נֶחְלְצָה מֵאֲחִי בַּעְלָהּ:
כסף משנה
8.
[In the above situation,] if the son whose [father's identity] is in doubt dies [childless], one of the two sons whose [father's identity] is known should first perform chalitzah with his wife, and afterwards the second should perform yibbum.15It is, however, forbidden for one of the sons to perform yibbum first, because it is possible that the deceased's wife is obligated to the other brother and must perform chalitzah.[The rationale is that if the deceased] was his brother, then he has performed yibbum. And if he is not his brother, but rather the son of the other father, his wife has already performed chalitzah with her husband's brother [and is permitted to remarry].
הלכה ט
מִי שֶׁהָלַךְ בַּעְלָהּ לִמְדִינָה אַחֶרֶת וְשָׁמְעָה שֶׁמֵּת וְנִשֵּׂאת וְאַחַר כָּךְ בָּא הַבַּעַל הָרִאשׁוֹן וּמֵתוּ שְׁנֵיהֶן וְלָזֶה אַחִין וְלָזֶה אַחִין. אֶחָיו שֶׁל זֶה וְאֶחָיו שֶׁל זֶה חוֹלְצִין וְלֹא מְיַבְּמִין:
כסף משנה
9.
[The following rules apply when] a woman's husband traveled to another country, his wife heard that he died and [on this basis] married another man, and then her first husband returned. If both husbands die [childless],16Even if only one of the husbands dies childless, his brother still must perform chalitzah and may not perform yibbum. and they both have brothers, one of each husband's brothers should perform chalitzah, but not yibbum.17Yibbum is prohibited because, as stated in Hilchot Gerushin 10:5, such a woman is forbidden to both her husbands and must be divorced by both of them.The chalitzah performed by the brother of the first husband is required by Scriptural law, while the chalitzah performed by the brother of the second husband is mandated by Rabbinic decree.
הלכה י
חָמֵשׁ נָשִׁים שֶׁהָיָה לְכָל אַחַת מֵהֶן בֵּן יָדוּעַ וְנִתְעַבְּרוּ חֲמִשְׁתָּן וְיָלְדוּ כְּאֶחָד בְּמַחֲבוֹאָה אַחַת חֲמִשָּׁה בָּנִים אֲחֵרִים וְנִתְעָרְבוּ הַיְלָדִים וְהִגְדִּילוּ הַתַּעֲרוֹבוֹת וְנָשְׂאוּ נָשִׁים וּמֵתוּ חֲמִשָּׁה הָאֲנָשִׁים וְנָפְלוּ חָמֵשׁ הַנָּשִׁים לִפְנֵי חֲמִשָּׁה הַבָּנִים הַוַּדָּאִין שֶׁאֵין אֶחָד מֵהֶן יוֹדֵעַ אֵי זוֹ הִיא אֵשֶׁת אָחִיו כֵּיצַד תַּקָּנָתָן. אַרְבַּע מֵהֶן חוֹלְצִין לְאַחַת תְּחִלָּה וְהַחֲמִישִׁי יִשָּׂא זוֹ שֶׁנֶּחְלְצָה אַרְבַּע חֲלִיצוֹת עַל כָּל פָּנִים:
כסף משנה
10.
[The following rules apply when there were] five women who each had a son whose identity had been established, and then the five women all gave birth together in a hiding place to five other sons, and the identities of the second group of sons became confused to the extent that it was not known who gave birth to whom. The sons whose identity became confused matured and married, and then these five men died [childless] and their five wives fell before the wives of the sons whose identity was known, but none of these sons knows who is the wife of his brother.What must be done [so that these women can remarry]? Four [of the sons whose identity was known] perform chalitzah for one of the wives first, and the fifth son should marry her after she has performed chalitzah four times.
הלכה יא
כֵּיצַד. אִם אֵשֶׁת אָחִיו הִיא הֲרֵי יִבֵּם אוֹתָהּ. וְאִם אֵינָהּ אֵשֶׁת אָחִיו הֲרֵי הִיא אֵשֶׁת אָח אֶחָד מֵאַרְבָּעָה וַהֲרֵי חָלְצוּ לָהּ אַרְבַּעְתָּן תְּחִלָּה. וְכֵן הַשְּׁנִיָּה חוֹלְצִין לָהּ אַרְבָּעָה וְהָאֶחָד מִן הָאַרְבָּעָה יִהְיֶה זֶה שֶׁנָּשָׂא הָרִאשׁוֹנָה וְהַחֲמִישִׁי יִשָּׂאֶנָּה. עַד שֶׁנִּמְצְאוּ הַבָּנִים הַחֲמִשָּׁה נָשְׂאוּ הֶחָמֵשׁ נָשִׁים אַחַר שֶׁנֶּחְלְצָה כָּל אַחַת מֵהֶן אַרְבַּע חֲלִיצוֹת:
כסף משנה
11.
What is implied? If the woman was his brother's wife, he has performed yibbum. And if she is not his brother's wife, she is the wife of the brother of one of the other four, and they all performed chalitzah with her first.Similarly, the second woman should have four [of the sons whose identity was known] - including the one who married the first [of the widows]18I.e., each of the sons whose identity is known should marry one of the widows instead of having one marry more than one. When one son marries more than one widow, we are certain that he did not perform yibbum twice. Either - or neither - of the women he married could have been his brother's widow, but there was only one widow, not two. Our Sages preferred having each of the sons marry one woman and thus take the chance that they were all fulfilling yibbum, rather than have one marry more than one. See Yevamot 98b. - perform chalitzah with her, and the fifth one should marry her. [This process should be continued] until the five sons have married the five [widows] after each one performed chalitzah four times earlier.
הלכה יב
וּלְעוֹלָם הִזָּהֵר בְּכָל הַסְּפֵקוֹת הַלָּלוּ בְּעִקָּרִים אֵלּוּ. שֶׁכָּל מִי שֶׁנִּסְתַּפֵּק לְךָ שֶׁמָּא בַּת חֲלִיצָה הִיא לְאִישׁ זֶה אוֹ אֵינָהּ צְרִיכָה לַחֲלִיצָה מִמֶּנּוּ. אֵינָהּ נִתֶּרֶת לְהִנָּשֵׂא לְזָר עַד שֶׁיַּחֲלֹץ לָהּ אוֹתוֹ הָאִישׁ. וְכָל מִי שֶׁיִּסְתַּפֵּק לְךָ שֶׁמָּא בִּיאָתָהּ אֲסוּרָה עַל אִישׁ זֶה בֵּין מִדִּבְרֵי תּוֹרָה בֵּין מִדִּבְרֵי סוֹפְרִים אֵינָהּ מִתְיַבֶּמֶת לוֹ. וְכָל שֶׁנֶּחְלְצָה חֲלִיצָה מְעֻלָּה אוֹ נִבְעֲלָה בְּעִילָה כְּשֵׁרָה הֻתְּרָה צָרָתָהּ לְזָר:
כסף משנה
12.
When dealing with questionable situations of this nature, one should always have these principles at hand: When there is a doubt whether a woman is required to perform chalitzah with a particular man or not, she is not permitted to marry another man until that [first] man performs chalitzah with her.Whenever there is a doubt whether a woman is forbidden to engage in relations with a man - whether because of a Scriptural prohibition or a Rabbinic prohibition - she should not perform yibbum with him.
Whenever a woman has performed a "superior chalitzah"19See Chapter 5, Halachah 10. or "acceptable relations,"20See Chapter 5, Halachah 9. another woman who was married to the same husband is permitted to marry another man.
הלכה יג
וְעַל דֶּרֶךְ זוֹ תָּבִין וְתוֹרֶה בְּכָל הַסְּפֵקוֹת שֶׁיֶּאֶרְעוּ לְעִנְיַן יִבּוּם וַחֲלִיצָה שֶׁהֲרֵי בֵּאַרְנוּ כָּל הָעִקָּרִין שֶׁעֲלֵיהֶן תִּסְמֹךְ וְתֵדַע מִי הוּא שֶׁחוֹלֵץ וּמִי הוּא שֶׁמְּיַבֵּם וּמִי הִיא הַפְּטוּרָה מִן הַחֲלִיצָה וּמִן הַיִּבּוּם וּמִי הִיא הָרְאוּיָה לְיַבֵּם: סְלִיקוּ לְהוּ הִלְכוֹת יִבּוּם וַחֲלִיצָה בְּסִיַּעְתָּא דִּשְׁמַיָּא
כסף משנה
13.
Following the above patterns, you will be able to understand and rule with regard to any questionable situations that will arise with regard to yibbum and chalitzah. For we have explained all the fundamental principles on which one should rely. You will know who should perform chalitzah, who should perform yibbum, who is not obligated to perform chalitzah or yibbum and who is fit to perform yibbum.With God's help, this concludes "The Laws of Yibbum and Chalitzah."