Can you explain the concept of non-duality and the devotee's union with Sai as described in Chapter 52?

Chapter 52 uses several powerful analogies to explain the advanced spiritual concept of non-duality, where the devotee merges completely with the Guru. It states that when a devotee takes refuge at Sai’s feet, any sense of duality vanishes. The devotee relinquishes their "I-ness" and becomes one with Him. The chapter compares this union to a river entering the ocean and forgetting its separate identity as a river, or to two lamps embracing to become a single, unified light. Other metaphors used in Chapter 52 include salt instantly becoming one with the ocean it enters, and the scent being inseparable from camphor, illustrating the complete dissolution of the devotee's individual self into the singular consciousness of Sai.