The text in Chapter 16 explicitly addresses this question, offering a clear reason for his incarnation. Despite being hailed as the 'King of Yogis,' the Stainless (Niranjana), and the one beyond attributes (Gunatita), Sai Baba took on a physical form for a compassionate purpose. The chapter states that he has taken this body for the sake of helping others and specifically to uplift the poor and the lowly. By donning the 'cloak of ignorance,' he is able to impart knowledge to the ignorant and provide sweet instruction to his devotees.
Why did Sai Baba, described as the 'King of Yogis,' take on a physical human body?
π Chapter 16