According to the beginning of Chapter 19, what is the nature of Sai and the author's desire regarding Him?

The introduction to Chapter 19 describes Shri Sadguru Sainath in profound terms, identifying Him as the Supreme Reality, or Brahman. It states that Sai is the object that resides in everything, from the smallest atom to the vast universe, being both 'subtler than the subtlest and greater than the greatest.' Faced with this formless and all-pervading reality, the author expresses a heartfelt desire. As mentioned in the chapter, a wish arose in the author's heart to give a tangible form, color, and shape to this Supreme Reality in order to behold it with physical eyes, making the abstract concept of Brahman accessible through the beloved form of Sai.