To one who has not received the Buddha-mind, it seems very mysterious. Even people who have had a glimpse cannot always recognize it. This recognition cannot be explained, but can only be done by one who has already experienced it at a deep level. A good master has had many deep experiences and frequently can ascertain someone’s level of attainment just by looking at him. Very often affirmation comes through master and disciple asking each other questions, or the disciple describing his experiences to the master. One who has seen self-nature for the first time could not recognize another’s experience, nor is he ready to accept disciples.

The chance of a practitioner getting the Buddha-mind depends on his developing a “great ball of doubt, ” which drives him to diligent and energetic practice.

During retreat the master tries to bring each student to this state of great doubt, for only then is it possible to create an opening through which the Buddha-mind can enter. The Ch’an master will use different methods to do this, according to the student’s state of mind, personality, and accomplishment. So how I deal with a student depends on my sense of the student’s mental state. I call this a spontaneous perception-response. I don’t reflect on how I should deal with each student. I don’t form an idea that one student needs this, another needs that. If it is time to scold or beat, I scold or beat. If it is time to console or encourage, I console or encourage. I am just a mirror. The student’s perception of me is a perception of himself..

— Getting The Buddha Mind by Master Sheng-Yen (page 13-14)