1,945. When Brother A Dies, Followed by Wife B
Yibum v’Chalitzah 7:11
Let’s say there were three brothers, two of whom were married to sisters and one of whom was married to an unrelated woman. One of the brothers married to a sister died so the brother married to the unrelated woman performed yibum with his widow. Later, the sister of this yevama died, followed by the brother who had performed yibum. The result is that both of his widows fall to the remaining brother, who is now single. In such a case, these women have no obligation in chalitzah or yibum: the sister of this man’s late wife is prohibited to him because she was the sister of his wife when his brother died. This renders her forbidden to him forever as his brother’s wife, like the wife of a brother who was not alive during his brother’s lifetime. The other woman is prohibited as the first woman’s co-wife.
Yibum v’Chalitzah 7:12
Similarly, if two brothers are married to sisters and one of them dies, then the wife of the other brother dies, the widow is prohibited to this brother forever because she was prohibited at the time. However, if a man divorces his wife, remarries her and dies, she is permitted to the surviving brother. Even though she was prohibited to him during the late brother’s lifetime, she became permitted when he divorced her, with the result that she was permitted when he died.