Baha’u’llah had never claimed to be a prophet and that it was ‘Abdu’l-Baha who had imputed this claim to him.

Just a few years after ‘Abdu’l-Baha’s accession to office he [Muhammhad 'Ali] instituted legal proceedings against him and declared in court that Baha’u’llah had been merely a holy man who had lived in seclusion engaged in prayer and meditation; he stated that Baha’u’llah had never claimed to be a prophet and that it was ‘Abdu’l-Baha who had imputed this claim to him.

(Making the Crooked Straight: A Contribution to Bahá'í Apologetics, by Udo Schaefer, p. 716)