In the Book of Íqán Bahá’u’lláh explains that these prophecies about the sun, moon and stars, the heavens and the earth, are symbolical and are not to be understood merely in the literal sense. The Prophets were primarily concerned with spiritual, not material, things; with spiritual, not with physical, light. When They mention the sun, in connection with the Day of Judgment, They refer to the Sun of Righteousness. The sun is the supreme source of light, so Moses was a sun for the Hebrews, Christ for the Christians, and Muḥammad for the Muslims. When the Prophets speak of the sun being darkened, what is meant is that the pure teachings of these spiritual Suns have become obscured by misrepresentation, misunderstanding and prejudice, so that the people are in spiritual darkness. The moon and stars are the lesser sources of illumination, the religious leaders and teachers, who should guide and inspire the people. When it is said that the moon shall not give her light or shall be turned into blood, and the stars shall fall from heaven, it is indicated that the leaders of the churches shall become debased, engaging in strife and contention, and the priests shall become worldly minded, concerned about earthly instead of heavenly things. The meaning of these prophecies is not exhausted by one explanation, however, and there are other senses in which these symbols can be interpreted. Bahá’u’lláh says that in another sense the words “sun,” “moon,” and “stars” are applied to the ordinances and instructions enacted in every religion. As in every subsequent Manifestation the ceremonies, forms, customs and instructions of the preceding Manifestations are changed in accordance with the requirements of the times, so, in this sense the sun and moon are changed and the stars dispersed.