1,866. The Prohibition of a Yevama's Relatives

Yibum v’Chalitzah 1:12

When a brother marries a widow, all the other widows become prohibited both to him and to any other brothers. If one of them is intimate with one of the other widows, they violate the commandment that her brother-in-law have relations with her (Deuteronomy 25:9), i.e., it is only permitted with her and not with any other woman from the household. A prohibition inferred from an obligation is considered the violation of an obligation. Similarly, once one of the brothers performs chalitzah with one of the widows, both she and all the other widows become prohibited, both to him and to all the other brothers. They are prohibited under rabbinic law, having the status of a secondary level of forbidden relationship. Since their brother died without children, the primary prohibition against relations with his wife has been removed. Accordingly, if one of the brothers were to betroth her, the betrothal would be effective the same as with one of the secondary prohibited relationships.

Yibum v’Chalitzah 1:13

When a man performs chalitzah with his sister-in-law, both she and her relatives become prohibited to him; this includes her mother and her daughter. Similarly, she may not marry his son or his brother. Even secondary prohibited relations, like her daughter's granddaughter, are prohibited to him, and she is prohibited to his son’s grandson. Bottom line, she is the functional equivalent of a divorced wife. If the widow dies while the bond of yibum still exists with her brother-in-law, he may not marry these relatives of hers, the same as if she were his wife and predeceased him. These prohibitions are rabbinic enactments. The surviving brother may marry the sister of a widow with whom he did not perform chalitzah, as well as any other of her relatives.