Based on the provided text, what texts did the Patil read for his "Satya-Sai vow" and why did he consider them significant?

For his "Satya-Sai vow," the Patil chose to read specific texts that were central to his devotion to Sai Baba. Chapter 13 explains that instead of the traditional Satyanarayan story, the Patil read the "modern Bhaktalilamrut," a work written by Das Ganu. Within this book's forty-five chapters, three were specifically about Sainath. The Patil considered these three chapters to be the "Satya-Sai story" itself, viewing them as the "best among all vows." Reading these chapters about Sai's character brought him boundless happiness and peace of mind, making them a cornerstone of the devotional practice he established.