1,941. If One of the Prohibited Yevamos Dies

Yibum v’Chalitzah 7:3

Let’s say that one of the brothers died, obligating his widow in yibum. After this, the other brother dies, obligating his widow, who is the sister of the first woman, in yibum, As long as both of these women are alive, they must perform only chalitzah to the exclusion of yibum, as has been discussed.

Yibum v’Chalitzah 7:4

If the second woman dies, the first becomes permitted again and may perform either chalitzah or yibum. If the first woman dies, the second remains prohibited; she must perform chalitzah to the exclusion of yibum. This is because she wasn’t in a position to perform yibum when the levirate obligation first arose. Similarly, if one of the brothers performed chalitzah with the second woman first, the first woman becomes permitted to the other brothers. This is because the conflict that prohibited her was resolved by the brother who performed chalitzah.