"The Tang Chinese equivalent for the title Vajramukti (Chinese: Chuan Fa; Japanese: Kempo) was a nominal approximation used by monks for that section of the Buddhist Vajramukti art concerned with ritualized movement practices which contained the principles of health preservation, weaponless self-defense and meditative insight.
"Fearful that the Buddha might die without teaching some vital important principle, one of his disciples asked him if there was any other teaching he had not so far shown them. The Buddha replied by taking up a handful of leaves from the ground and asking the disciple whether these leaves in his hand were greater in number than the leaves on the forest they were in. When the disciple replied that there were more leaves upon the trees than those in his hand, the Buddha said so it was with his teaching. What he had shown his disciples was compared to the leaves in his hand. What he could have taught, he compared to the leaves upon the trees in the forest.
The Buddha then said he did not have the clasped hand (Chinese: chuan shou) of the teacher, but rather he had the open hand (Chinese: kai shou) of a Buddha. Though there were many doctrines, he had concerned himself only with what was most important for those around him to attain enlightenment.
Thus, the term "clasped hand" used here (chuan) was thought to be appropriate to describe the Vajramukti method, as its mastery was considered an esoteric and difficult to understand lineage practice, taught by a few masters to even fewer students. By comparison, the ordinary (exoteric) teaching of the Buddha was an "open-handed teaching' (Chinese: kai shou fa).
The word chuan is etymologically related to the ideograph used to describe a manuscript text (also pronounced chuan) but using slightly different characters. We often find accounts of the Chinese Buddhist Sutras existing in two or more chuan for it is a term identifying a document which, have been written on manuscript paper is rolled up or folder, for protection and storage. This "turning inward to protect" action of the paper is what is meant by the title chuan for a written work. The ideography for clasped hand (chuan) also describes this same type of action in the fingers.
The suffix fa was the Chinese transliteration of the Sanskrit term dharma (teachings of the Buddha). Such a suffix was commonly used throughout Chinese Buddhism to represent not just the teachings themselves but all the arts, crafts, and practices associated with them. Thus it could also mean the techniques, methods, or manners of practice."
- Shifu Nagaboshi Tomio (Terence Dukes), The Bodhisattva Warriors, 1994, pp. 184-185. A scholarly presentation of these topics.