1,931. When One Yevama is Prohibited and the Other Isn't

Yibum v’Chalitzah 6:14

Let’s say that a man’s brother dies, leaving two widows, one forbidden to the yavam as a prohibited relation and one not. Just as the former has no levirate bond, neither do any other widows. This is based on Deuteronomy 25:9, “who did not build his brother’s house.” The Sages inferred from this that widows from a house where the yavam can marry any of them have a levirate bond; if the yavam can’t build part of that house, by which we mean that he may not marry one of the widows, then he shouldn’t build even the part that’s permitted to him. Accordingly, if one of the widows is forbidden as a prohibited relation, the other is also forbidden to him as his brother’s wife without any levirate bond.

Yibum v’Chalitzah 6:15

Pursuant to the previous halacha, let’s say that Reuven dies, leaving two widows, one of whom is forbidden as a prohibited relation to Shimon but both women are able to marry Levi. In such a case, the women of this house have no levirate bond to Shimon and both have a bond to Levi. Let’s say that Levi performs yibum with the widow who was not prohibited to Shimon, plus Levi had another wife. If Levi dies and his two widows fall to Shimon for chalitzah or yibum, they are both relieved of their obligation. One is prohibited because she was co-wives with a woman who is forbidden to Shimon as a prohibited relation and the other is forbidden because she was co-wives with the first. This is true whenever a woman is co-wives with a woman who was co-wives with a prohibited relation, etc. etc. As long as there’s no levirate bond, a widow is prohibited to the yavam as his brother’s wife.