What specific text did the Patil use for his 'Satya-Sai vow,' and why was it significant?

For his 'Satya-Sai vow,' the Patil used a book referred to in Chapter 13 as the 'modern Bhaktalilamrut,' which was written by Das Ganu. This book was significant because it contained stories of many devotees, but the Patil focused on a specific part of it. The text clarifies that within this book, the three chapters detailing the character of Sainath are themselves considered the 'Satya-Sai story.' By reading these specific chapters with love and devotion every Thursday, the Patil found boundless happiness and peace of mind. This act established a new tradition, equating the worship of Sai with the worship of Narayan.