How does the narrative use Damu Anna's story to illustrate the power of one-pointed faith in Sai Baba?

Chapter 25 explicitly frames the story of Damu Anna as a demonstration of a core principle: 'Once one-pointed faith is established, Sai wards off all the misfortunes of that devotee.' The chapter introduces him as a 'devotee who was devoted to Sai's feet' and immediately provides an example of this principle by noting that although he was childless, he was blessed with sons through Sai's grace. The narrative then sets up the story of the cotton business proposal as a further illustration, promising the reader that by listening, 'Sai's readiness to protect His devotees will be seen directly' and they will see how the 'Guru-Mother is an Ocean of Mercy.'