פירוש על יבמות 14:2

If one of them was of full faculty and one was a deaf-mute, and the husband of the deaf-mute dies, she goes free by virtue of being the sister of the wife. If the husband of the full faculty one dies, the husband of the deaf-mute must divorce his wife with a bill of divorce, and his brother's wife with chalitza.

Two brothers, one able minded and the other a deaf mute, and the deaf-mute is married to two able minded women, and one of them was a forbidden relation, and the deaf mute brother died, both of them are exempt from doing the refusal service or levirate marriage. If they both were able minded and one of them was married to two women, one of them was able minded and the other a deaf-mute, and the deaf-mute was a forbidden relation to his brother, the second woman who is able minded can do the refusal service but cannot be contracted into the levirate marriage.