According to Chapter 13, what specific text did the Patil use for his 'Satya-Sai vow' and why was it considered equivalent to a traditional vow?

According to the account in Chapter 13, the Patil used a modern text for his 'Satya-Sai vow' instead of traditional scriptures. Specifically, he would read from the 'Bhaktalilamrut', a book written by Das Ganu. Within this book, the Patil would read the three chapters dedicated to Sainath. These three chapters were considered to be the 'Satya-Sai story' and 'the best among all vows.' The text explains this practice was considered equivalent to a traditional vow because the Patil saw no difference between the divine figures, stating, 'There it is Narayan, here it is Sai; there is no difference in either.' This equivalence is why he performed the vow with the same auspicious celebration and offerings, starting a new custom in his village.