Can you explain the concept of dissolving duality and the role of the Sadguru as depicted in Chapter 40?

According to Chapter 40, Shri Sai Samarth has the power to destroy the sense of duality in a devotee, dissolving the separate feelings of 'me' and 'you.' This process is initiated when a devotee offers a full prostration and seeks exclusive refuge in Him. The chapter uses the powerful analogy of a river and an ocean, which have different names but are essentially one; when they meet, no difference remains. Similarly, when a devotee approaches the Sadguru with true devotion, the Guru grants them His own divine nature, making the unattainable attainable and merging the devotee's consciousness with the universal.