Describe Damu Anna's background and his specific vow related to the Ram Navami festival.

Damu Anna was a well-to-do person from Ahmednagar, specifically a wealthy Kasar (bronze-smith), who was a devout follower of Sai Baba. As Chapter 25 recounts, he faced the personal sorrow of having no children despite having two wives. However, through Sai's grace, he was eventually blessed with sons. In connection with this, he made a vow regarding the annual Ram Navami festival in Shirdi. For many years, he provided one of the two large new flags that were taken out in a procession. This was a vow he carried out with uninterrupted love and devotion, with the other flag being provided by the Nimonkars.