Based on the introduction, what is the author's stated motivation for writing this book, and how does this relate to the concept of selfless service?

The author's primary motivation for writing the book is explicitly stated in Chapter 1 as a directive from his Guru. Despite feeling inadequate and lowly, confessing his lack of deep scriptural knowledge, he undertakes the effort of writing solely "to fulfill the Guru’s word." This act demonstrates a profound sense of selfless service and obedience to his master. He sees himself as a mere instrument, a "blade of grass," carrying out a higher command. This humility and dedication to the Guru's instruction, rather than personal ambition or a desire for acclaim, frame the entire work as an act of devotion and service.