Can you explain the teaching of non-duality as presented in Chapter 40?

Chapter 40 of the Shri Sai Satcharitra explains the concept of non-duality, or the dissolution of separateness, through powerful metaphors. It states that Sai Baba destroys the "sense of duality" by dissolving the separate feelings of "me" and "you" for those who surrender to Him. This spiritual union is compared to a river meeting the ocean, where they become one essence despite having different names. The text elaborates that when a devotee seeks exclusive refuge in the Sadguru with true devotion, the Guru "grants them His own Guru-nature," thereby erasing the distinction between the devotee and the divine master.