It is apparent from the Guardian's writings that where
Bahá'u'lláh has expressed a law as between a man and a woman it applies,
mutatis mutandis, between a woman and a man unless the context should make this
impossible. For example, the text of the "Kitáb-i-Aqdas" forbids a
man to marry his father's wife (i.e. his step-mother), and the Guardian has
indicated that likewise a woman is forbidden to marry her step-father....
(The
Universal House of Justice, from a letter dated 28 April 1974 to an individual
believer; The Compilation of Compilations, vol. II, Women)
