According to Chapter 48, what distinguishes a true Sadguru from other spiritual teachers who may only have verbal knowledge?

Chapter 48 draws a sharp contrast between a true Sadguru and other teachers. It states that individuals who merely study the Vedas, explain Vedanta, or please audiences with talks about Brahman are not necessarily Sadgurus. The key differentiator, as explained in this chapter, is the presence of direct self-experience. While some teachers may have vast verbal knowledge and offer sweet-sounding explanations, this knowledge is described as 'verbally hollow' without personal realization. A Sadguru, in contrast, possesses both complete verbal knowledge and is a 'giver of direct, full experience,' making them uniquely qualified to enlighten disciples.