According to the final chapter, why was the book "Sai Leela" written and who was chosen to write it?

The book "Sai Leela," or the Satcharitra, was created to remember and document the experiences Sai Baba granted to His followers during His lifetime. Chapter 52 describes the text as supremely holy, containing stories of His true character intended to provide enlightenment for this world and the next. The chapter reveals that Sai Baba specifically chose Hemadpant to be the author, despite Hemadpant's feeling of being devoid of specialized knowledge. It is stated that Baba held his hand and caused this true life story to be written, with the inspiration for the book arriving after Baba had departed His physical body.