직지심체요절 (Anthology of Great Buddhist Priests' Zen Teachings — World's Oldest Movable Metal Type, 1377)

"...the heart-nature is unstained and inherently complete. Just depart from deluded conditions, and you are the Thus Come One Tathagata."

Zen Master Xuansu was once visited by a butcher who wished to provide an offering at his residence. The master happily went, and the assembly was surprised. The master said, "Buddha-nature is equal; the wise and the foolish are one. I simply teach those who can be taught; what difference is there?"

Zen Master Dadien was first interviewed by Shitou. Shitou asked the master, "Which one is your heart?" The master said, "The one that speaks." He was immediately shouted out. Ten days later, the master asked again, "The one from before is not it; besides that, what is the heart?" Shitou said, "Besides raising your eyebrows and blinking your eyes, bring your heart here." The master said, "There is no heart I can bring here." Shitou said, "So you have a heart, yet you say you have no heart? To say there is no heart is the same as slandering." The master had a great enlightenment at these words.

Zen Master Caoshan Danzhang had a monk who wore paper clothes and was called 'Paper-Clothing Practitioner.' He came from Dongshan. The master asked, "What is the matter of the Paper-Clothing?" The monk said, "Once the robe covers the body, all matters are as they are." He asked again, "What is the use of the Paper-Clothing?" The monk stood forward, bowed, and said, "Yes," then departed. The master laughed and said, "Do you understand what he meant by leaving?" "I do not understand what he meant by coming." The monk suddenly opened his eyes and asked, "What about the 'one spiritual true nature that does not borrow the womb'?" The master said, "That is not yet the subtle." The monk asked, "What is the subtle?" The master said, "It does not borrow, yet it borrows." The monk retired to the hall and passed away. The master composed a verse:

The awakened nature is round and bright, a formless body.
Do not use knowledge and views to falsely separate the close and the distant.
If a thought is different, then the mysterious essence is different.
If the mind is discordant, do not treat the Way as a neighbor.
If feelings differentiate the ten thousand dharmas, they sink into previous states.
If consciousness discerns many things, it loses the original truth.
If you fully understand within the phrase,
You will be the person of the past with nothing to do.
The master's way of awakening those of superior roots left no traces to follow.

Zen Master Mengshan said: "After the discovery, one should always enter the 'samadhi of true emptiness' to wash away the habits of dust from many lives. When the habits of dust are light and clear, one can know the events of this life after leaving the mother's womb, and the events of one, two, up to ten previous lives. If the habits of dust are completely purified, one can know the events of many lives. This is called the 'Divine Power of Knowledge of Past Lives.' Progressively, the ear-root, eye-root, and up to the six roots become pure. Those who can thoroughly clear all roots and dust, all penetrations, all samadhis, great wisdom, great eloquence, great divine power, and great skillful usage are all discovered from within the 'True Emptiness and True Aspect.'"