Arise, awake, and learn by approaching the excellent ones. The wise ones describe that path to be as impassible as a razor's edge, which when sharpened, is difficult to tread on.(Ka.Up. I.iii.14)
The master in that book is called Sri Ganesha and no doubt may have had elements of the famous Bhagavan Sri Ramana Maharshi of Tiruvanamalai in South India whom he visited in 1938. Ramana's teaching was the ancient one of atma vichara or self inquiry and it consisted of continuously asking 'who am I', analysing the answer that you come up with and thus by progressive discrimination arrive at the permanent basis of self awareness.
I am not sure how well the details of the visit are known generally but I found an account of it in a book put out by the Ashram called Talks with Sri Ramana Maharshi
Somerset Maugham, a well-known English author, was on a visit to Sri Bhagavan. He also went to see Maj. Chadwick in his room and there he suddenly became unconscious. Maj.Chadwick requested Sri Bhagavan to see him. Sri Bhagavan went into the room, took a seat and gazed on Mr.Maugham. He regained his senses and saluted Sri Bhagavan. They remained silent and sat facing each other for nearly an hour. The author attempted to ask questions but did not speak. Maj.Chadwick encouraged him to ask. Sri Bhagavan said, "All finished. Heart talk is all talk. All talk must end in silence only." They smiled and Sri Bhagavan left the room.