Can you explain the philosophical concept of moving from the Saguna to the Nirguna as presented in Chapter 52?

Chapter 52 explains that understanding the formless Self (Nirguna) requires first engaging with the form (Saguna). It states that 'Without entering the Saguna form, the light of the Self cannot be known' because the attributeless Parabrahma is difficult to grasp directly. The process involves meditating immensely on Sai's physical form. As devotion deepens, the Saguna form 'vanishes' from the mind, and the subtle nature of the Self manifests. Chapter 52 illustrates this union using the analogy of two lamps becoming one light, where the state of duality vanishes and only unity remains.