What is the origin story of the name 'Sai Baba' as explained in the book's introduction?

The name 'Sai Baba' originated from his very first encounter in Shirdi, as described in Chapter 0. When Maharaj, dressed in a kafni, cap, and dhoti, entered the Khandoba temple, a devotee of Khandoba named Mhalasapati saw him and welcomed him with the words 'Aavo Sai Baba,' which means 'Come, Sai Baba.' Maharaj accepted this name and was known by it for the rest of his life. The introduction even notes that when his testimony was taken in a commission, he stated, 'They call me Sai Baba,' confirming the name Mhalasapati gave him.