In this formula, the philosophy of the Middle Way Madyamika and the metaphysics of the Avatamsaka School flow together. (H. Dumoulin, Zen Buddhism: A History, p. 219.)

(2) Hua-t'ou. The words hua-t'ou and kung-an (Jap. koan) are sometimes used interchangeably.
 

[Hua-t'ou], lit., "word-head;" the point, punch line, or key line of a koan, the word or phrase in which the koan resolves itself when one struggles with it as a means of spiritual training .... In the famous koan Chao-chou, Dog, for example, mu is the [hua-t'ou]. Many longer koans have several [hua-t'ous]. (Shambhala Dictionary of Buddhism and Zen, p. 246.) 

(3) The Buddha holding up a flower.
 

The "special transmission outside the orthodox teaching" began with the famous discourse of Buddha Shakyamuni on Vulture Peak mountain. At that time, surrounded by a great host of disciples ... the Buddha is said only to have held up a flower without speaking. Only Kashyapa understood and smiled ... With this, the first transmission from heart-mind to heart-mind took place. The Buddha confirmed Mahakashyapa, as his enlightened student was called henceforth, as the first Indian patriarch in the lineage of [Zen] transmission. (Ibid., p. 261.) 

(4) Almost all sutras in Buddhism were taught following a specific request from one of the leading disciples. A notable exception is the Amitabha Sutra, which Buddha Sakyamuni preached without being asked. According to Buddhist commentaries, this is because Pure Land teachings, while simple in appearance, can be understood in full only by the Buddhas and Bodhisattvas. Therefore, it would not have occurred to anyone to request that it be taught. 

(5) See "Awakening of the Faith Treatise."  Please note, however, that the Pure Land school preceded the coming of the Sixth Patriarch by a few centuries.

(6) See the following passages:
 

Dr. Suzuki is generally associated with the Zen school, so it is often a matter of surprise to hear that he translated many Pure Land Buddhist texts into English and nourished a belief that Pure Land rather than Zen might be the form of Buddhism most suitable for Westerners. (John Snelling, The Buddhist Handbook, p. 216.) 

Most Buddhists in the world, by far the vast majority, practice a Faith or devotional form of worship. Dr. D.T. Suzuki strongly believed that the direction American Buddhism would take was towards Shin Buddhism [Pure Land] and its practice of Faith. It may turn out at this time that most Westerners, originally seeking personal enlightenment, will find themselves choosing a devotional path. (Ryushin Sarah Grayson inButsumon, Fall 1989.)

(7) This passage refers to the noumenon (transcendental) aspect of Pure Land: "if the mind is pure, the land is pure." The phenomenal (popular) aspect of Pure Land is expressed in the following passage from the Amitabha Sutra: 
 

The Buddha then said to Shariputra the Elder: "Westward from here and beyond ten billion Buddha-lands there is a world called Utmost Happiness. In that land there is a Buddha called Amida, who is right now preaching the Dharma." (Hozen Seki, tr., Buddha Tells of the Infinite: the "Amida-kyo," p. 13).

(8) To illustrate the extreme difficulty of rebirth in the human realm (as opposed to the lower realms of hell, hungry ghosts or animality), Sakyamuni Buddha compared it to the likelihood that a blind sea turtle, surfacing from the depths of the ocean only once every century, would encounter a tree trunk in which to nest. Skeptics beware: millions of humans may be born each year in this world, but how many more viruses come into being each moment on a tiny mound of earth? 

(9) "Serene, reflective meditation," "working on a hua-t'ou (kung-an)." These two approaches possibly refer to the principal meditation practices of the Soto and Rinzai schools of Zen, respectively. 

(10) Afflictions may be termed "guest dusts." They are "guests" because they come and go, unlike our empty and still True Nature. They are "dusts" because they stick to and defile the True Mind, just like the dust which covers a bright mirror and prevents it from reflecting the objects before it. 

(11) This passage is a reference to the Surangama Sutra, a key Zen text which teaches three basic causes of Birth and Death: love-attachment, greed and killing. Master Han-Shan highlighted the first cause for the benefit of his audience. 

(12) People may practice Buddha Recitation for various reasons, including warding off danger or achieving rebirth in favorable circumstances in the human or celestial realms. Master Han-Shan emphasized that the true goal should be ending the cycle of Birth and Death. 

(13) Poison; panacea: at the ultimate level, Buddha Recitation, too, is a false thought that should be discarded.
 

This Dharma-door [Pure Land] fights poison with poison. False thinking is like poison, and unless you counter it with poison, you will never cure it. Reciting the Buddha's name is fighting false thinking with false thinking. It is like sending out an army to defeat an army, to fight a battle to end all battles. (Master Hsuan Hua.)

Sentient beings' minds are never at rest but are filled with a continuous stream of deluded thought (monkey mind, horse-like mind). According to Han-Shan and most Patriarchs, it is easier to change and convert this stream gradually (from impure thought to pure thought) than to stop the process entirely at all times. 

Buddha Recitation is a panacea because, when practiced correctly, it can heal all the diseases of the mind (greed, anger, delusion). It is also a remedy for persons of all capacities under all circumstances. 

(14) This idea is expressed by the image of horizontal escape:
 

"Vertically" and "horizontally" are figures of speech, which can readily be understood through the following example. Suppose we have a worm, born inside a stalk of bamboo. To escape, it can take the "hard way" and crawl all the way to the top of the stalk. Alternatively, it can look for or poke a hole near its current location and escape "horizontally" into the big, wide world. The horizontal escape, for sentient beings, is to seek rebirth in the Pure Land of Amitabha.

(15) Discipline, i.e., keeping the precepts. There are many sets of precepts, for monks, nuns and laymen. The five basic precepts for laymen are not to kill, steal, engage in illicit sex, lie or consume intoxicants. All of these numerous precepts, however, may be summarized by three injunctions: to avoid all evil; to cultivate all virtues; to benefit all sentient beings. 

(16) Mind-Only Pure Land: see Buddhism of Wisdom and Faith, para. 27, "Buddha Recitation and the Four Realizations." 

(17) See the following passage from the Surangama Sutra:
 

Suppose a man with good fresh eyes looks steadily into the bright, shining space of the sky without glancing about or winking. After long staring, there arise contaminations of the eyes and in the emptiness of space, he sees fantastic blossoms and many other strange phantasms. These fantastic blossoms that the contaminated eyes see in the open space of the sky come neither from the sky nor from the eyes. (Goddard, A Buddhist Bible, p. 156.)

(18) Thus, thusness, suchness:
 

Reality is beyond all words and descriptions, so in referring to it, Buddhists often use the term "thusness." (Garma C. Chang)
 

(20) See the following passage:
 

Han-shan did not write any commentary on the Pure Land Sutra, and it is not clear how he places it in the Hua-yen [Avatamsaka] classification scheme. On the one hand, he regards the Western Paradise as the most expedient land in the innumerable Hua-yen pure lands. On the other hand, he seemed to have considered the Pure Land teaching as a special teaching that lies outside the usual scheme of classification. (Sung-peng Hsu, A Buddhist Leader in Ming China, p. 149.)

(21) There are more than 200 sutras teaching about Pure Land in the Buddhist canon (Encyclopedia of Buddhism).

(22) See the concept "Third lifetime" in Glossary. 

(23) See the following passage, by the late founder of the Buddhist Lodge and Buddhist Society (London), on the true goal of all Buddhist practice: 
 

In the West, the need for some guidance in mind-development was made acute ... by a sudden spate of books which were, whatever the motive of their authors, dangerous in the extreme. No word was said in them of the sole right motive for mind-development, the enlightenment of the meditator for the benefit of all mankind, and the reader was led to believe that it was quite legitimate to study and practice mindfulness, and the higher stages which ensue, for the benefit of business efficiency and the advancement of personal prestige. In these circumstances, Concentration and Meditation, ... was compiled and published by the [British] Buddhist Society, with constant stress on the importance of right motive, and ample warning of the dangers, from a headache to insanity, which lie in wait for those who trifle with the greatest force on earth, the human mind. (Christmas Humphreys, The Buddhist Way of Life, p. 100.) 

(24) See the following passage from D.T. Suzuki: 
 

Buddhist theology has a fine comprehensive theory to explain the manifold types of experience in Buddhism, which look so contradictory to each other. In fact the history of Chinese Buddhism is a series of attempts to reconcile the diverse schools ... Various ways of classification and reconciliation were offered, and ... their conclusion was this: Buddhism supplies us with so many gates to enter into the truth because of such a variety of human characters and temperaments and environments due to diversities of karma. This is plainly depicted and taught by the Buddha himself when he says that the same water drunk by the cow and the cobra turns in one case into nourishing milk and in the other into deadly poison, and that medicine is to be given according to disease. This is called the doctrine of [skillful] means ... (The Eastern Buddhist, Vol. 4, No. 2, p. 121.) 

(25) Other-power: "Invisible assistance -- provided by the Buddhas and Bodhisattvas of Healing -- can be a potent aid in this process [of elimination of greed, anger and delusion]. This assistance often is described as stemming from the force of their fundamental vows." (Raoul Birnbaum, The Healing Buddha, p. xv.) This power, is, of course, common to all Buddhas and Bodhisattvas. 

(26) See the following passage from D.T. Suzuki: 
 

Jiriki (self-power) is the ... [wisdom] aspect of enlightenment and tariki (other-power) is the ... [Great Compassion] aspect of the same. By [wisdom] we transcend the principle of individuation, and by [Great Compassion] we descend into a world of particulars. The one goes upwards while the other comes downwards, but this is our intellectual way of understanding and interpreting enlightenment, in whose movement however there is no such twofold direction discernible. (The Eastern Buddhist, Vol. 3. No. 4, p. 314.)

(27) As a historical perspective, the roots of Pure Land go back to Ancient India, albeit the tradition was not emphasized there:
 

Although a cult dedicated to Amitabha Buddha worship did arise in India, piety toward this Buddha seems to have been merely one of many practices of early Mahayana Buddhism. (Elizabeth ten Grotenhuis, in Joji Okazaki, Pure Land Buddhist Painting, p. 14.)

When Mahayana Buddhism spread to China, however, Pure Land ideas found fertile ground for development. In the fourth century, the movement crystallized with the formation of the Lotus Society, founded by Master Hui Yuan (334-416), the first Pure Land Patriarch. The school was formalized under the Patriarchs T'an Luan (Jap. Donran) and Shan Tao (Jap. Zendo). Master Shan Tao's teachings, in particular, greatly influenced the development of Japanese Pure Land, associated with Honen Shonin (Jodo school) and his disciple, Shinran Shonin (Jodo Shinshu school) in the 12th and 13th centuries. 

Note: An early form of Buddha Recitation can be found in the Nikayas of the Pali Canon: 
 

In the Nikayas, the Buddha ... advised his disciples to think of him and his virtues as if they saw his body before their eyes, whereby they would be enabled to accumulate merit and attain Nirvana or be saved from transmigrating in the evil paths ... (D.T. Suzuki, The Eastern Buddhist, Vol. 3, No. 4, p. 317.) 

(28) See the following passage on Bodhisattva practice, taken from the well-known "Practices and Vows of the Bodhisattva Samantabhadra": 
 

Because of living beings, they bring forth great compassion. From great compassion the Bodhi Mind is born; and because of the Bodhi Mind, they accomplish Supreme, Perfect Enlightenment. (Avatamsaka Sutra, ch. 40.) 

(29) This is clearly shown in the Avatamsaka Sutra, particularly chapter 26 which describes the last phases of practice of a Bodhisattva before final Buddhahood. In that chapter, it is taught that in each and every single stage, the actions of the Bodhisattva "never go beyond Buddha Recitation":
 

This is a summary of the Tenth Stage of enlightening beings [Bodhisattvas], called Cloud of Teaching ... Whatever acts they undertake, whether through giving, or kind speech, or beneficial action, or cooperation, it is all never apart from thoughts of Buddha [Buddha Recitation], the Teaching, the Community ... (Thomas Cleary, tr., The Flower Ornament Scripture, Vol. II, p. 111.) 

(30) See the following passage:
 

The [Longer Amitabha Sutra] ... which was in existence before a.d. 200, describes a discourse offered by the Buddha Sakyamuni ... in response to questions of his disciple Ananda. Sakyamuni tells the story of the Bodhisattva Dharmakara, who had for eons past been deeply moved by the suffering of sentient beings and who had determined to establish a Land of Bliss where all beings could experience emancipation from their pain ... In the presence of the eighty-first Buddha of the past, Lokesvararaja, Dharmakara made forty-eight vows relating to this Paradise, and promised that he would not accept enlightenment if he could not achieve his goals ... When, after countless ages, Dharmakara achieved enlightenment and became a Buddha, the conditions of his [18th] vow were fulfilled: he became the Lord of Sukhavati, the Western Paradise, where the faithful will be reborn in bliss, there to progress through stages of increasing awareness until they finally achieve enlightenment. (Elizabeth ten Grotenhuis, in Joji Okazaki, Pure Land Buddhist Painting, p. 14-15.) 

(31) The life story of the Venerable Angulimala is one of the most moving accounts in the Theravada canon. After killing ninety-nine persons, Angulimala was converted by the Buddha, repented his evil ways and joined the Order: 

One day as he went on his round for alms he saw a woman in labor. Moved by compassion, he reported this pathetic woman's suffering to the Buddha. He then advised him to pronounce the following words of truth, which later became known as the Angulimala Paritta (Mantra) ... 

"Sister, since my birth in the Arya clan [i,e., since my ordination] I know not that I consciously destroyed the life of any living being. By this truth may you be whole and may your child be whole." 

He went to the presence of the suffering sister ... and uttered these words. Instantly, she delivered the child with ease. (Narada Maha Thera, The Buddha and His Teaching, p. 124.) 

(32) Faith is an important element in all Buddhist traditions, but it is particularly so in Pure Land. See the following passage from the Avatamsaka Sutra:
 

Faith is the basis of the path, the mother of virtues, Nourishing and growing all good ways ... Faith can increase knowledge and virtue; Faith can assure arrival at enlightenment. (Thomas Cleary, tr. The Flower Ornament Scripture, vol. 1, p. 331.)

(33) The pervasiveness of Pure Land teaching is such that its main practice, Buddha Recitation, is found in both the Esoteric and Zen schools. In Pure Land, Buddha Recitation is practiced for the purpose of achieving rebirth in the Land of Amitabha Buddha as a stepping-stone to Buddhahood. In the Esoteric school, the aim is to destroy evil karma and afflictions, obtain protection against demons and generate blessings and wisdom in the current lifetime. In Zen, the koan of Buddha Recitation is meant to sever delusive thought and realize the Self-Nature True Mind. The ultimate goal of all three schools is, of course, the same: to achieve Enlightenment and Buddhahood. 

(34) See Master Hsuan Hua's explanation:
 

The Bhikshu was slowly taking a walk. Here the seven days refer to the seven limbs of enlightenment. The Bhikshu is leisurely taking a stroll. Leisurely refers to "stopping" (samatha); while strolling refers to "contemplation" (vipasyana). The Bhikshu dwells neither in confused thought nor does he linger in quiescence.He is cultivating the Pratyutpanna Samadhi in which the Buddhas of the Ten Directions are clearly revealed before one's eyes.