The first story involves a disciple of Hui-neng, Nan-yueh Huai-jang (677-744). Huai-jang observed a monk named Ma-tsu (709-788), who had a habit of doing zazen all day long. Realizing this was no ordinary monk, Huai-jang asked Ma-tsu, "Why are you constantly doing zazen?" Ma-tsu answered, "To attain buddhahood." Huai-iang picked up a brick and started rubbing it vigorously. After a while Ma-tsu asked, "What are you doing?" Huai-jang said, "I'm making a mirror from this brick." Ma-tsu said, "That's absurd. You can't make a mirror from a brick." Huai-jang said, "Indeed. And how is it possible to become a budgha by doing zazen?" Thereupon Ma-tsu asked, "What should I do?" Huai-jang said, "When the ox won't pull the cart, do you beat the cart or the ox?" Ma-tsu did not know how to reply. So Huai-jang said, "Are you doing zazen to attain Ch'an or to become a buddha? If it's Ch'an, Ch'an is neither sitting nor lying dawn; if it's buddhahood, Buddha has no form. Since the Dharma has no abiding form, there should be no grasping, no rejection. Your attachment to sitting prevents you from realizing buddhahood, and it kills Buddha besides." Ma-tsu became a disciple of Huai-jang and eventually a great master himself.

This story teaches that true zazen is not just a matter of sitting, however dedicated or perfected. To do zazen with Ma-tsu's original understanding will bring some benefits. But it is impossible to attain Ch'an simply by perfecting the external form of zazen. Self-nature is to be found in what Huai-jang called the "mind-ground,', not in the realm of form. Later Ma-tsu reiterated this point in his concept of "ordinary mind" (p'ing-ch'ang). One sense of this expression is a mind that is involved in the ordinary world, moving as usual but not clinging to anything. Another sense comes from the root meanings of p'ing and ch'ang, which suggest a mind that is "level" and "constant," or in a state of constant equanimity. In either sense, there is no attachment.