[If] one of them was forbidden to one [brother] by the ervah prohibition, and the second one was forbidden to the other [brother] by the ervah prohibition —- the one forbidden to this [brother] is permitted to the other [brother], while the one forbidden to that [brother] is permitted to this [brother]. This is what was meant by the statement: [If] her sister is her [fellow] yevamah she may either perform chalitzah or be taken in yibum.

[If there were] three brothers, [and] two of them were married to two sisters, or [to] a woman and her daughter, or daughter's daughter, or son's daughter -— they require chalitzah but may not be taken in yibum. R' Shimon, however, releases [them]. [If] one of them was forbidden to him by the ervah prohibition, he is forbidden to her but permitted to her sister. [If it was] a prohibition by commandment or because of sanctity, she requires chalitzah but may not be taken in yibum.

[If there were] three brothers, [and] two of them were married to two sisters, while one was unmarried; [if] the husband of one of the sisters died, and the unmarried one performed maamar with her, and then his second brother died —- Beis Shammai say: His wife [remains] with him, while the other is discharged as his wife's sister; but Beis Hillel say: He must send away his wife with [both] a divorce and chalitzah, and his brother's wife with chalitzah. About this it was said, “Woe unto him concerning his wife, and woe unto him concerning his brother's wife.”

[If there were] three brothers, [and] two of them were married to two sisters, while one was married to a stranger; [if] the husband of one of the sisters died, and the one married to the stranger married his wife and [then] died —- the first one is discharged as [his] wife's sister, and the second as her co-wife. [If] he performed maamar with her and then died —- the stranger requires chalitzah but may not be taken in yibum.  [If there were] three brothers, [and] two of them were married to two sisters, while one was married to a stranger; [if] the one married to the stranger died, and the husband of one of the sisters married his wife and [then] died —- the first one is discharged as [his] wife's sister, and the second as her co-wife. [If] he performed maamar with her and then died —- the stranger requires chalitzah, but may not be taken in yibum.