Why does the author interrupt the main storyline in Chapter 2 to tell a different story?

The author, Hemadpant, explains in Chapter 2 that he is deliberately pausing the main life story of Sai Baba to fulfill a promise he made to his listeners in the previous chapter. He had promised to tell the story of how he was given the name "Hemadpant." Since this name is used to credit him at the end of every chapter, he anticipates the readers' natural curiosity about its origin. He feels that sharing this sub-story is appropriate at this juncture and believes that the impulse to do so is an inspiration from Sai Baba himself. After satisfying this curiosity, he promises that the sequence of Sai’s life story will then continue.