Can you explain the origin and practice of the 'Satya-Sai vow' as initiated by the Patil?

The 'Satya-Sai vow' was a new tradition started by the Patil out of gratitude for his miraculous healing, as described in Chapter 13. This practice was modeled on the traditional Satyanarayan vow. The Patil began performing the Satya-Sai vow every Thursday after bathing. Instead of reading the usual Satyanarayan story, the Patil would lovingly read the three chapters about Sainath from the 'Bhaktalilamrut' written by Das Ganu. He performed this vow with a joyful mind, friends, and relatives, offering the same abundance of Naivedya as in the traditional vow, seeing no difference between Narayan and Sai. This practice then became a custom in his village.