Can you explain the origin of the name 'Sai Baba' based on the account in Chapter 0?

The name 'Sai Baba' originated from the very first words spoken to him upon his arrival in Shirdi. As narrated in Chapter 0, when Maharaj entered the Khandoba temple, he was greeted by a devotee of Khandoba named Mhalasapati. Upon seeing Maharaj, who was dressed in a kafni and cap, Mhalasapati welcomed him by saying 'Aavo Sai Baba,' which translates to 'Come, Sai Baba.' Maharaj held onto this name for the rest of his life. The text confirms this by mentioning that when his testimony was taken in a commission and he was asked his name, he simply replied, 'They call me Sai Baba.'