Shirdi Sai baba was a great man, much revered as a Saint who is even worshipped as a divine incarnation in several parts of India. His life and achievements were mentioned in detail in the work Sai Satcharitra.
In chapter 27 of Sai Satcharita there is a reference to Shirdi Sai Baba emphatically advising his disciple to read Vishnu Sahasranama...."Oh Shama, this book is very valuable and efficacious, so I present it to you, you read it. Once I suffered intensely and My heart began to palpitate and My life was in danger. At that critical time, I hugged this book to My heart and then, Shama, what a relief it gave me! I thought that Allah Himself came down and saved Me. So I give this to you, read it slowly, little by little, read daily one name at least and it will do you good.