In comparing these two texts the reader will be impressed with the most important and most striking change Bodhi-Dharma made in his quotation, which is the substituting of _pi-kuan_ for _chüeh-kuan_. _Pi_ ordinarily means “wall” or “precipice,” and is often found in combination with _li_, “standing,” in such phrases as _pi li wan jên_ 壁立萬仞, to describe an unscalable wall, or figuratively to represent the attitude, for instance, of Acala-Vidyārāja standing straight up. What was the reason of Dharma’s changing _chüeh_, “to awaken,” or “to be enlightened” into a word which apparently has no organic relation to the following _kuan_, “to perceive,” or “to contemplate”? The novel combination is a very important one, for it alters the sense of the whole context in which it occurs. Tao-hsüan, the author of the _Biographies_, refers to Dharma’s _tai ch‘êng pi kuan_, Mahayanistic wall-contemplation, in his commentary notes to Zen, as the most meritorious work Dharma achieved in China.[f85] For this reason he is often spoken of as the _pi-kuan_ Brahman, that is, wall-contemplating Brahman, and in Japan the monks belonging to the Soto school of Zen are supposed to follow the example of the founder of their religion when they keep up the practice of sitting facing the wall while meditating. But this is evidently a superficial interpretation of the phrase _pi-kuan_; for how could mere wall-gazing start a revolutionary movement in the Buddhist world as is implied in Tao-hsüan’s life of Dharma?[f86] How could such an innocent practise provoke a terrible opposition among scholars of those days? To my view, _pi-kuan_ has a far deeper meaning, and must be understood in the light of the following passage in the _Records_, which is quoted from a work known as the _Pieh Chi_[4.30] meaning some special document of prior existence: “The master first stayed in the Shōrinji (Shao-lin-szŭ) monastery for nine years, and when he taught the second patriarch, it was only in the following way: ‘Externally keep yourself away from all relationships, and, internally, have no pantings (or hankerings, 喘 _ch‘uan_) in your heart;[f87] when your mind is like unto a straight-standing wall you may enter into the Path.’ Hui-k‘ê tried variously to explain [or to discourse on] the reason of mind, but failed to realise the truth itself. The master simply said, ‘No! No!’ and never proposed to explain to his disciple what was the mind-essence in its thought-less state, [that is, in its pure being]. [Later] said Hui-k‘ê, ‘I know now how to keep myself away from all relationships.’ ‘You make it a total annihilation, do you not?’ queried the master. ‘No, master,’ replied Hui-k‘ê, ‘I do not make it a total annihilation.’ ‘How do you testify your statement?’ ‘For I know it always in a most intelligible manner, but to express it in words—that is impossible.’ Thereupon, said the master, ‘That is the mind-essence itself transmitted by all the Buddhas. Harbour no doubts about it.’”