Chapter III: Sleep And Death
The astral body thus returns to its pristine home during sleep, and on awakening brings with it into life newly strengthened forces. All this finds expression in the refreshment which a healthy sleep affords. As the further exposition of Occult Science will reveal, the home of the astral body is of far wider compass than the more obvious physical environment to which the physical body belongs. While as a physical being man is a member of the Earth, his astral body belongs to worlds wherein other heavenly bodies are contained besides our planet Earth. The astral body therefore, during sleep, enters a Universe to which other worlds than the Earth belong. But this can only be made fully clear in the further course of our explanations.
Read this passage in another edition