How does Chapter 52 explain the concept of non-duality and the merging of a devotee with the Guru?

Chapter 52 uses powerful metaphors to illustrate the state of non-duality achieved when a devotee unites with the Guru. It explains that when a devotee takes refuge in Sai, He does not leave any sense of duality in them, comparing this to a river forgetting its 'river-ness' upon embracing the ocean. Another analogy provided is that of two lamps becoming one when they embrace; the state of duality vanishes instantly, leaving only a single, unified light. This demonstrates the complete dissolution of the individual self into the singular consciousness of the Guru.