‘The forty-second patriarch was Liangshan. He studied with Tongan Guanzhi and served him. Tongan asked him, “What is the business beneath the patched robe?” Liangshan had no answer. Tongan said, “Studying the Buddha Way and still not reaching this realm is the most painful thing. Now, you ask me.” Liangshan asked, “What is the business beneath the patched robe?” Tongan said, “Intimacy.” Liangshan was greatly awakened.
From Keizan Jokin’s commentary: ‘What was the original intention in getting people to leave home and escape the passions? It was just to get them to arrive at Buddha’s wisdom and vision. Taking the trouble to establish Zen communities and gathering together the four groups (monks and nuns, laywomen and -men) were only for the purpose of clarifying this matter…
Of course, even if any numbers of Buddhas came and tried to offer you this one great matter, even their powers would not suffice in the end. Therefore, this is not a path you can pass on to your children, or a path you can receive from your father. You have to do it yourself, awaken to it yourself, and acquire it yourself. Even though you practice for infinite eons, self-authentication and self-awakening happen in an instant.’
I would add that it is certainly not necessary to put on a patched robe to be awakened, but wearing one and not fully arousing the aspiration to awaken is indeed a great sadness.