[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.”