Based on Chapter 37, explain the philosophical reason for the soul's entrapment in the cycle of birth and rebirth (Samsara).

Chapter 37 delves into the root cause of Samsara, the eternal cycle of death and rebirth. The text explains that the ultimate reality, Parabrahman, pervades everything, yet a soul deluded by ignorance fails to see this unity. The fundamental error that subjects a soul to this cycle is the knowledge of difference and separation. When an individual holds the belief, 'Parabrahman is different from me; I am not that, I am something else,' this sense of being separate from the ultimate reality ensures their continued bondage. As the chapter states, death follows birth and rebirth follows death for one who maintains this illusion of duality.