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

Chapter 52 uses several vivid analogies to illustrate the concept of non-duality, where the distinction between the devotee and Sai vanishes. It explains that when a devotee takes refuge at Sai's feet, they relinquish their 'I-ness' and become one with Him. This is compared to a river entering the ocean and forgetting its 'river-ness' to become the ocean itself. Other examples include salt instantly becoming one with the ocean upon entering it, and two lamps embracing to become a single, unified light where the state of duality disappears. The chapter reinforces this by asking rhetorically if scent can be separate from camphor or light from the sun, emphasizing a complete and essential merger.