What is the primary theme discussed in Chapter 15 of the Shri Sai Satcharitra, and what analogy is used to illustrate it?

Chapter 15 focuses on the prayers of loving devotees to Sai and how he graciously grants them his vision. To illustrate this divine relationship, the chapter uses a powerful analogy of a mother cat and her kittens. As detailed in the text, the kittens persistently cling to their mother out of love, which eventually causes her milk to flow, and she embraces them affectionately. Chapter 15 explains that, in the same way, a devotee's unwavering attachment and devotion to Sai's feet will melt his heart and cause his grace to flow towards them, ensuring they achieve the supreme goal.