How does Damu Anna's story exemplify the concept of 'one-pointed devotion' that the chapter introduces?

The story of Damu Anna serves as a direct case study for the concept of 'one-pointed devotion' introduced at the start of Chapter 25. The chapter begins by stating that Sai desires one-pointed devotion and that a faithful devotee lacks nothing. The author then presents Damu Anna's tale specifically to prove this point, framing it as a story that shows how "Sai wards off all the misfortunes of that devotee" once such faith is established. Damu Anna's long-standing, uninterrupted vow of providing a flag for the Ram Navami festival, as well as his blessing of receiving sons, are shown as the fruits of his dedicated and focused faith, making his life a clear example of the rewards of one-pointed devotion.