What keeps a person trapped in the cycle of birth and death, and how is this related to the concept of Brahman?

The text explains that the cycle of worldly existence, or Samsara, where death follows birth and rebirth follows death, is perpetuated by a specific form of ignorance. As stated in Chapter 37, this ignorance is the belief in a fundamental separation between oneself and the ultimate reality, Parabrahman. The thought "Parabrahman is different from me; I am not that" is what subjects a soul to this eternal cycle. The text clarifies that the same divine principle, Brahman, pervades everything from the creator down to a blade of grass, but it appears as if it were not Brahman to a soul deluded by this false sense of difference.