Tell me about Damu Anna's background and the vow he undertook for Sai Baba.

Damu Anna was a well-to-do person from Ahmednagar, identified in Chapter 25 as a wealthy Kasar, or bronze-smith. He was a great devotee, deeply devoted to Sai's feet. His story is told to showcase Sai's readiness to protect His followers. Damu Anna had a long-standing vow related to the Ram Navami festival in Shirdi, which he carried out with great love. This vow involved providing one of the two large flags for the annual procession. He undertook this after Sai's grace resolved his issue of being childless, blessing him with sons.