Can you explain the story about the woman who wanted to fast, as described in Chapter 32?

Chapter 32 recounts the story of a woman who came to Shirdi with a strong desire to have Sai Baba's darshan and intended to fast without food for three days. However, the chapter explains that her firm resolve was broken. Baba intervened and had her prepare puranpolis. Not only did she make them, but she was also made to eat them to her heart's content. Through this act, Baba taught her a valuable lesson: the blessed act of wearing out the body for the sake of others represents true and supreme welfare, a principle he wanted her to understand so she would never forget it.