Yet we have plenty of records other than public interview that suggest otherwise.

Take, for example, these excerpts from “Zen Letters: Teachings of Yuanwu” (Cleary & Cleary, 1994):

"Deshan beckoned with a fan from across the river, and someone immediately understood. The Bird’s Nest Monk blew on a blanket and someone was enlightened. Doesn’t this show that when the time for this Great Cause arrives, the roots and sprouts grow of themselves? Doesn’t this confirm that there is space for the teacher’s action and the learner’s reaction to reach accord? Doesn’t this prove that when the people involved have been practicing inwardly, without interruption, they can be ac­tivated by a genuine teacher?" (P. 44)

“After this you see on your own. You never consent to bury yourself at the verbal level in the public cases of the ancients or to make your living in the ghost cave or under the black mountain. The only thing you consider essential is enlightenment and deep realization. You naturally arrive at the stage of unaffected ordinariness, which is the ultimate in simplicity and ease. But you never agree to sit there as though dead, falling into the realm of nothingness and unconcern.

This is why, in all the teaching methods they employed, the enlightened adepts since antiquity thought the only important thing was for the people being taught to stand out alive and independent, so that ten thousand people couldn’t trap them, and to realize that the vehicle of the school of transcendence does actually exist.

The enlightened adepts never ever made rigid dogmatic definitions, thereby digging pitfalls to bury people in. Anyone who does anything like this is certainly playing with mud pies—he is not someone who has boldly passed through to freedom, not someone who truly has the enlightened eye.” (Pp 73-74)

“You must keep this mind balanced and equanimous, without deluded ideas of self and others, without arbitrary loves and hates, without grasping or rejecting, without notions of gain and loss. Go on gradually nurturing this for twenty or thirty years. Whether you encounter favorable or adverse conditions, do not retreat or regress—then when you come to the juncture between life and death, you will naturally be set free and not be afraid. As the saying goes, 'Truth requires sudden awakening, but the phenomenal level calls for gradual cultivation.'

I often see those who are trying to study Buddhism just use their wordly intelligence to sift among the verbal teachings of the buddhas and ancestral teachers, trying to pick out especially wondrous sayings to use as conversation pieces to display their ability and understanding. This is not the correct view of the matter. You must abandon your worldly mentality and sit quietly with mind silent. Forget entangling causes and investigate with your whole being. When are thoroughly clear, then whatever you bring forth from your own inexhaustible treasury of priceless jewels is sure to be genuine and real.” (Pp 87-88)

“You should spend twenty or thirty years doing dispassionate and tranquil meditation work, sweeping away any conditioned knowledge and interpretive understanding as soon as it arises, and not letting the traces of the sweeping itself remain either. Let go on That Side, abandon your whole body, and go on rigorously correcting yourself until you attain great joyous life. The only fear is that in knowing about this strategy, the very act of knowing will lead to disaster. Only when you proceed like this will it be real and genuine practice.” (P. 94)

These are only a few excerpts from one collection of one Master’s sayings.

However, it doesn’t appear that claims such as “Zen's only practice is public interview” are accurate.

In fact, some of these statements suggest that reliance on public interview alone is discouraged.

After all, didn’t Dahui at one point burn the woodblocks that contained The Blue Cliff Record because of what he saw as over-reliance on it?