According to Chapter 1, why does the author invoke Goddess Saraswati, and how is she related to Sai?

The author invokes Goddess Saraswati, the daughter of Brahma, because she is the Goddess of Speech, and the text questions how any literature could be achieved without her grace. Chapter 1 details this invocation, where the author asks her, who rides the swan and holds the Brahma-veena, to make his tongue her own swan to ride upon. The purpose is for her to make the author an instrument to share the nectar of Sai's life. Following this, the text equates Sai with the deity, stating that "Sai himself is Goddess Saraswati, holding the Omkara-veena in hand, singing his own life story for the salvation of his devotees."