In this book Osho transmits the idea of not losing the essence of the main idea ... It is the "Sannya".

Description from Sannyas Wiki:

Osho discusses how Zen came into being and describes the remarkable people who spread it across the vastness of the Asian continent. This book contains great stories about Lao Tzu, Bodhidharma, Confucius, Bokuju and others. Osho's humor and insight give the reader a feeling of timelessness, as though the reader has come to Lao to ask about "the way," is being shocked by Bodhidharma's spontaneous totality or is being awakened by Seddyo's koan. And of course, Osho himself...a mystic's mystic!