The book was occasioned by four questions. Haji Mirza Sayyid Muhammad, a maternal uncle of the Bab still undecided about his nephew's claim, visited Baghdad in early 1861 and was encouraged to put his difficulties in writing: how could the Bab be the promised Qaim when the traditions' signs, the sun rising in the west, the appearance of the Beast, had not literally occurred. Baha'u'llah's reply, filling a substantial book, answers by reframing what prophecy is. The first part surveys the history of the Manifestations, Noah, Abraham, Moses, Jesus, Muhammad, showing that each was rejected by the learned of the prior religion on precisely such literalist grounds, and reads the gospel prophecy of the darkened sun and falling stars as the eclipse of former religious authority and the descent of its clergy.
Terms such as resurrection, judgment, life and death are expounded as spiritual conditions: the dead are those who refuse the new revelation, the clouds that obscure the promised one are human perceptions of his ordinary humanity. The second part unfolds the station of the Manifestation, unity in essence between the messengers, distinction in mission, and describes the true seeker's path of detachment from imitation and hearsay. Though the Bab is its immediate subject, the argument prepared the ground for Baha'u'llah's own declaration two years later, and the book's categories became the lens through which Bahais read all scripture.