What is the origin story behind the name 'Sai Baba' as explained in the introduction?

The name 'Sai Baba' was spontaneously given to Maharaj upon his arrival in Shirdi. Chapter 0 recounts that when he entered the Khandoba temple, dressed in a kafni, cap, and dhoti, a devotee of Khandoba named Mhalasapati saw him and welcomed him with the words 'Aavo Sai Baba,' which means 'Come, Sai Baba.' Maharaj held onto this name until the end. The text further notes that when his testimony was taken in a commission and he was asked his name, he replied, 'They call me Sai Baba,' confirming his adoption of the name given by Mhalasapati.