Brahman, as the Atman, expresses itself when the man is awake, he is the bird, the crab, and the lotus. While the bird and lotus analogy for the human soul is commonly found in Vedic literature, this is the first and isolated mention of crab analogy, states Deussen. It may refer to a lost Upanishad, or Schrader suggests that the chaotic movements of a crab that is difficult to follow, might be implied in the crab simile here.
