[If] two competent brothers were married to two sisters, one a deaf-mute and one competent, and the competent husband of the deaf-mute [sister] died, what should the competent husband of the competent [sister] do? [Nothing, because] she is released as his wife's sister. [If] the competent husband of the competent [sister] died, what should the competent husband of the deaf-mute [sister] do? He must discharge his wife with a bill of divorce, and his brother's wife with chalitzah.