According to Chapter 45, what is the relationship between Sai's physical departure, his literary form, and the devotee's spiritual practice?

Chapter 45 presents a sophisticated relationship between Sai's physical departure, his literary form in the Satcharitra, and the devotee's spiritual path. The chapter explains that while Sai's physical form vanished upon completing his incarnation's work, he concurrently established his form in the hearts of devotees through meditation, shifting the focus from external to internal worship. As detailed in Chapter 45, the Satcharitra then becomes his "literary form," a tangible source of remembrance. Engaging with it by listening to the stories with a concentrated mind is described as a "speech-sacrifice" (Vag-yagna) and a holy act, ensuring the devotee's spiritual connection and progress continues in the absence of the Guru's physical presence.