sentence: Bahá'u'lláh called him the "Expounder" of his word, meaning that only `Abdu'l-Bahá had the right to say what Bahá'u'lláh's writings mean.
modified: fix grammar: Bahá'u'lláh called him the "Expoundest" of his word, meaning that only `Abdu'l-Bahá had the right to say what Bahá'u'lláh's writings mean.