Chapter 13 introduces the 'Satya-Sai vow.' What were the origins of this vow, how was it performed, and what was its underlying philosophy?

The 'Satya-Sai vow' originated with the Patil from Birgaon as a way to express his immense gratitude after being cured by Sai Baba's grace. As explained in Chapter 13, it was modeled after the traditional Satyanarayan vow, which people undertook to overcome crises. The Patil's version, however, was dedicated to Sai. On Thursdays, after bathing, he would read the three chapters about Sainath written by Das Ganu in the 'Bhaktalilamrut.' This reading constituted the core of the vow, which was performed with a joyful mind and accompanied by the same abundance of offerings (Naivedya) as the traditional ritual. The underlying philosophy was one of non-difference between deities, as the text explicitly states, "There it is Narayan, here it is Sai; there is no difference in either," thus equating devotion to Sai with worship of the Supreme Being.