Why does the author invoke Goddess Saraswati in Chapter 1, and how is she identified with Sai?

The author invokes Goddess Saraswati, the daughter of Brahma, for the successful composition of the book. As Chapter 1 explains, she is the Goddess of Speech and the Mother of the World, without whose grace no literature can be achieved. She is described as holding the Brahma-veena, riding a swan, and wearing white clothes. The author prays for her to make him an instrument to share the nectar of Sai's life. Significantly, the text states that Sai himself is Goddess Saraswati, holding the Omkara-veena and singing his own life story for the salvation of his devotees.