Based on Chapter 20, what is the significance of a Guru in comprehending profound spiritual texts like the Upanishads?

Chapter 20 strongly emphasizes the indispensable role of a Guru in understanding deep spiritual knowledge. It states that the Upanishads contain the essence of the Vedas, and grasping their meaning is very difficult without the grace of Hari (God) and a Guru. The text explicitly refutes the idea that a scholar can comprehend these texts through their own efforts, claiming that the hidden truth will not be revealed even at the end of an era without a Guru's grace. For one who is humble, detached, and devoted to the Guru's feet, Chapter 20 assures that the hidden meanings of this science of Self-knowledge will open up automatically.