What is the central theme of Chapter 4, and who are the intended readers as described in its introduction?

The central theme of Chapter 4 is to explain the profound reason why saints take an incarnation on Earth, a question posed at the beginning of the chapter. It explores the circumstances of spiritual decline that necessitate their arrival. The introduction of the chapter directly addresses the readers as 'O great listeners' and humbly asks for their focused attention. The text identifies the intended audience as the 'unique devotees of Sai,' inviting them to drink the 'nectar of Sai’s stories' and become filled with joy, thus highlighting the devotional purpose of the narrative.