Yevamos, Chapter 4, Mishnah 7. The mishnah opens with the laws of inheritance following chalitzah: "HaCholetz liyvimto - harei hu ke'echad min ha'achin lenachalah" - one who performs chalitzah with his yevamah has the same status as the rest of the brothers with regard to inheriting the deceased brother. We do not say that since he performed chalitzah and thereby withheld yibum from her he should be penalized and forfeit his share in the inheritance; rather, he is like any one of the brothers. Had he performed yibum, however, he would have inherited his brother alone.
"Ve'im yeish sham av - nechasim shel av" - if the father of the brothers is still alive, the inheritance goes to him: once the mitzvah of yibum has lapsed, the father takes precedence over any of his sons, and he inherits his deceased son in place of the brothers.
"HaKoneis es yevimto - zachah benechasim shel achiv" - one who actually performs yibum inherits all the property of his deceased brother. This is the benefit gained by performing yibum.
"Rabbi Yehudah omer: bein kach uvein kach, im yeish sham av - nechasim shel av" - according to Rabbi Yehudah, whether through chalitzah or through yibum, as long as the father is alive the property goes to the father. In his view, the ruling that the yavam acquires the property of his deceased brother applies only when there is no father. The Gemara brings that even when there is a father, the property goes to the yavam.
The prohibition of her relatives after chalitzah:
From here the mishnah moves on to discuss the fact that after chalitzah a man is forbidden to all the relatives of the woman with whom he performed chalitzah, and she is forbidden to his relatives: "HaCholetz liyvimto - hu asur bikroveseha vehi asurah bikrovav". Chalitzah is considered a form of divorce, and just as the relatives of a divorcee are forbidden to her husband by Torah law, so the relatives of a chalutzah are forbidden to him by rabbinic law.
The mishnah then lists the relatives forbidden to him:
"Be'imah" - the mother of the chalutzah.
"Uve'eim imah" - her mother's mother.
"Uve'eim aviha" - her father's mother.
"Uvevitah" - her daughter.
"Uvevas bitah" - her daughter's daughter.
"Uvevas benah" - her son's daughter.
"Uva'achosah bizman shehi kayemes" - her sister, and she is forbidden to him only as long as the chalutzah is alive.
"Ve'echav mutarin" - the remaining brothers, who did not perform chalitzah, are permitted to all these relatives, since once chalitzah was performed the zikah lapsed. As long as a zikah exists, a man can become forbidden to the relatives of the woman to whom he is bound by that zikah; but after chalitzah there is no longer any zikah, and there is no prohibition here. Only the one who actually performed the chalitzah, whose chalitzah resembles divorce, is forbidden to her relatives.
The relatives to whom she is forbidden:
The father of the one who performed chalitzah - because of the prohibition of one's daughter-in-law.
His father's father - because of "his son's daughter-in-law," a prohibition that is only rabbinic, and nevertheless applies to a chalutzah as well.
His son - since she is like his father's wife by rabbinic law.
Some have noted that in all three of these cases she was already forbidden on account of her deceased husband: the father of the one who performed chalitzah is also the father of the deceased brother; his father's father - since she is his son's daughter-in-law and is therefore a sheniyah to him; and his son - since she is his father's brother's wife.
The mishnah continues its list of relatives:
"Uveven beno" - the son of his son, since she is "his father's father's wife," a sheniyah by rabbinic law, and this prohibition too applies to a chalutzah.
"Uve'achiv" - his brother, since she is his brother's wife.
"Uveven achiv" - since she is his father's brother's wife.
The tzarah of the chalutzah and the tzarah of her relatives:
The mishnah then teaches a novel ruling: "Mutar adam bikrovas tzaras chalutzaso" - once chalitzah was performed the zikah lapsed, and he became forbidden only to the relatives of the chalutzah herself; but to the relatives of her tzarah he is permitted, and there is no reason to forbid them.
By contrast: "Ve'asur betzaras krovas chalutzaso" - for each of the relatives of the chalutzah who became forbidden to him, her tzarah is forbidden to him as well.
And what is the reason for this? The Gemara explains that when a woman receives chalitzah, she often brings along one of her relatives - her sister, for example - and people are liable to confuse the two and think that it was the sister who received the chalitzah. Now, the tzarah of the woman with whom he performed chalitzah is always forbidden to him, since she too is the widow of his deceased brother, and once chalitzah was performed both of them became forbidden. Because of the concern that people will confuse which of them received the chalitzah - she or her relative - the Sages forbade to him the tzarah of her relative as well.