Why does the author of the Sai Satcharitra pray to Goddess Saraswati in the opening chapter?

In Chapter 1, the author prays to Goddess Saraswati, the deity of speech and knowledge, because he feels that composing such a profound book is impossible without her divine grace. He asks the 'Mother of the Universe and the Vedas' to make him an instrument to share the 'nectar of the life of the capable Sai' with everyone. The author describes her as holding the Brahma-veena and riding a swan, and he implores her to make his tongue her swan to ride upon, signifying a request for divine eloquence and inspiration. As Chapter 1 reveals, just as with Ganesha, Sai himself is also identified with the goddess, being described as Saraswati singing his own life story for his devotees.