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

Monk Bao'en, because Fayan asked, "What person did you see arrive?" He replied, "I saw Zen Master Qingfeng arrive." Fayan said, "What words did he speak?" He replied, "I once asked, 'What is the student's own self?' Qingfeng said, 'The child of fire and water a metaphorical reference to the impossibility of seeking fire with fire comes seeking fire.' Fayan said, 'How do you understand the elder's words?' He replied, 'The child of fire and water belongs to fire; taking fire to seek fire, taking oneself to seek oneself.' The Master said, 'I knew you would not understand the Buddha-dharma. If it were like this, you would not have arrived at today.' Then, restless, he rose and returned halfway, saying, 'He is a great teacher of five hundred people; he said I am not. If it is not, there must be a reason.' He returned to apologize and asked, 'What is the student's own self?' The Master said, 'The child of fire and water comes seeking fire.' At those words, he was suddenly enlightened.
Formerly, Zen Master Yangqi met Zen Master Ciming. Every time he went to the Abbot's quarters to ask for guidance, Ming would say, "You understand it yourself; I am not as good as you." Yangqi felt deep frustration. One day, they met on a narrow road during a heavy rain. Yangqi grabbed Ciming and said, "Today, if you do not give me an explanation..."

Understanding the essence, the Master said, "For the body of prajna wisdom, ultimately it is pure and empty; there is not a single thing to be attained. This is what is called: 'There is no dharma truth to preach; this is what is called preaching the dharma truth.'"
Zen Master Fojian instructed the assembly, citing a monk who asked Zhaozhou: "What is the meaning of 'not moving'?" Zhaozhou made a flowing water gesture with his hand. The monk had an insight. Another monk asked Fayan: " 'Not grasping at characteristics, like 'Thusness' the absolute reality, unmoving.' How does one not grasp at characteristics and see the unmoving?" Fayan said, "The sun rises in the east and sets in the west." The monk also had an insight. If one can see through the words of these three masters, one will know that while the whirling wind may level the mountains, they are fundamentally and always still; while the rivers may compete in their flow, they are naturally not moving. This is the meaning of 'Thusness' unmoving not moving.
Zen Master Luoshan once asked Shishuang: "When phenomena do not stop arising and ceasing, what then?" Shishuang said, "You must immediately become like cold ashes and withered wood. A single thought lasts ten thousand years; be completely clear, without a single spot." Luoshan did not agree. He went to Yantou and asked as before. Yantou shouted, "Who is it that arises and ceases?" Luoshan was instantly relieved.