Can you explain the philosophical concept of oneness versus duality as presented in Chapter 14 of the Satcharitra?

Chapter 14 delves into the philosophical teachings of oneness and duality, presenting a core tenet of non-duality. It teaches that the same Essence found within one's own body is present in the entire universe. Surrendering to this Essence allows one to perceive oneness in all things. Conversely, the intellect that establishes duality, or manifoldness, is labeled as "pure ignorance" and is the cause of the endless cycle of birth and death. According to this chapter, liberation from this cycle comes through the Guru's teachings, which purify the mind and allow one to realize their true nature. The text concludes this point by stating that from Brahma down to a blade of grass, everything is pervaded by Brahman.