Is Khul' (redemption from marriage) valid when the husband or wife is terminally ill?

Primary text

The Khul' during illness is valid, regardless of whether the sick party is the husband, the wife, or both. This is because Khul' is a form of commutative transaction (mu'awadah), which is valid during illness, similar to a sale. There is no known dispute regarding the validity of the Khul' itself in this state.