According to the teachings in Chapter 37, what is the primary cause for an individual being trapped in the cycle of birth and death (Samsara)?

Chapter 37 teaches that the fundamental reason a person is subject to the perpetual cycle of Samsara is the ignorance-born delusion of being separate from the ultimate reality. The text explicitly states that one who holds the belief, "Parabrahman is different from me; I am not that, I am something else," is always subject to death. This perceived duality and knowledge of difference is what fuels the eternal wheel of existence where death follows birth and rebirth follows death. The implication is that liberation comes from realizing the non-dual truth of one's identity with the all-pervading Brahman.