Chapter 20 presents a dual nature of Sai Baba. Can you explain how he is described as both formless and in a physical form, and for what purpose?

Chapter 20 of the Sai Satcharitra presents a profound concept about Sai Baba's nature, describing him as a 'Siddhashram' or abode of the perfected. The text states that Sai is 'originally formless' but took on a physical form specifically for the sake of his devotees. It uses the metaphor of an actor, saying Baba accepted the role of the actress 'Maya' and played his part perfectly. This chapter explains that he assumed a form so that his devotees could experience relief from the fatigue of worldly life through his sight and feel his constant presence, which drives away delusion.