What is the author's stated motivation for writing Chapter 49, even while admitting the impossibility of fully describing Sai's greatness?

The author's motivation, as articulated in Chapter 49, is rooted in the desire to share the immense bliss he experiences from Sai's grace. He uses the analogy of tasting a sweet delicacy and feeling the need to bring friends and virtuous people to the feast, believing that "the bliss of the self-essence doubles" when shared. Although he acknowledges that his speech cannot possibly describe the inconceivable art of the Unfathomable, he feels compelled to create this "culinary arrangement of essence" because the remembrance of Sai's stories, given by Sai's own grace, moves him to complete the book for other listeners.