For what reason does the author invoke Goddess Saraswati in Chapter 1, and how is she identified with Sai Baba?

The author invokes Goddess Saraswati because she is the goddess of speech, knowledge, and literature, and he believes no literary work can be accomplished without her grace. As explained in Chapter 1, he pleads for her to make him the instrument to narrate the 'nectar of the life of the capable Sai to everyone.' She is described as holding the Brahma-veena and riding a swan. Parallel to the identification with Ganesha, Chapter 1 makes the profound statement that 'Sai himself is Goddess Saraswati, holding the Omkara-veena in hand, singing his own life story for the salvation of his devotees.' This presents Sai Baba as the ultimate source of his own biography, singing it through the author.