"The transmission of the True Law （the Buddhist teaching） from a Zen master to his disciple by personal contact without using the words and letters of the scriptures."
"A Zen expression for the authentic transmission of Buddha-dharma from master to students and dharma successors within the lineages of transmission of the Zen tradition. This term， which is usually translated 'transmission from heart-mind to heart-mind '
became a central notion of Zen. It comes from the Platform Sutra of Hui-neng， the Sixth Patriarch of Ch'an （Zen） in China. He points out that what is preserved in the lineage of the tradition and 'transmitted' is not book knowledge in the form of 'teachings' established in sacred scriptures but rather an immediate insight into the true nature of reality， one's own
immediate experience， to which an enlightened master can lead a student through training in the way of Zen."