The text mentions a 'necklace of nine gems' and 'ninefold devotion' in relation to Baba. What's the context for this?

In Chapter 33, the phrase 'necklace of nine gems' is used metaphorically to describe the profound significance of Sai Baba's touch. The text explains that for the person whom Baba's hand touched, this touch is like a precious necklace symbolizing the treasure of 'ninefold devotion and love' and serves as a form of remembrance of Baba. This concept is mentioned in the context of a story involving a note, making nineteen, and Appa being given nine. The text also foreshadows that the full meaning of this, along with a 'nine-donation,' would become clearer upon hearing the story of Baba giving up his body, or Mahasamadhi.