What is the 'Satya-Sai vow' mentioned in the text, and how did this tradition begin?

The 'Satya-Sai vow' is a devotional practice that was started by the Patil out of profound gratitude for his healing by Sai Baba. As detailed in Chapter 13, this practice was inspired by the common tradition of performing a Satyanarayan vow to overcome crises. The Patil adapted this by creating a vow dedicated to Sai. On Thursdays, he would read the three chapters about Sainath from Das Ganu's 'Bhaktalilamrut,' which he considered the 'Satya-Sai story.' This ritual, complete with offerings and celebration, became a custom in his village, equating the grace of Sai with that of Narayan.