The following has been adapted and edited in a modern way from Master Ma Yeuh-Hang's Book on Tuishou

Taichichuan Ching (Classic by Chang San-feng)
Tai Chi is infinity; the absolute, or ‘no limit’, from which It is created. It’s mechanism of dynamic and static movement is the mother of yin and yang. Thus, in movement, it separates; in stillness, it combines. It must be neither overdone nor underdone. Stretching is found in bending. Meeting hardness with softness is to ’go along with.’ In a favorable position, contrary to your opponent, you are ‘sticking to’. A rapid attack calls for a rapid response, a slow offensive a slow response. Despite innumerable changes and variations, the basic principle remains the same. Your skill in the mastery of strength will be gradually obtained through practicing the zhe (the measures of martial art). From mastery of strength, you may advance step by step to the ‘miraculous’ state of being. But without sufficiently long pursuit of the exercise, you cannot gain sudden enlightenment.
Hui-lin-din-jin (lift the head and straighten the neck) and chi-cheng-tan-dian (sink the chi to the lower abdomen). Maintain your poise, that is, without distortion or deviation. Your strength seems to be suddenly hiding and suddenly appearing. If the left side is weighted, you are ready to change to empty at the left. If the right side is weighted, you are ready to empty at the right.
When your strength is directed to the top, you should be higher than your opponent , and lower when you draw it downward. Advancing, your strength is further from your opponent when you advance, and closer to when you retreat. A feather cannot be added, nor can a fly land. Your strength and intentions should be undetectable, while you can anticipate the others.
This is the reason the master became invincible. There are many unorthodox ramifications in this art. The postures are varied, but they never rely on strength to beat a weaker person, nor on swiftness to subdue a slower one. These are mainly the inherited instincts not related to skills from learning.
Consider the expression of using four ounces to deflect a thousand-pound: it is evident that this feat is not achieved by the overwhelming strength. Indeed, how delightful it is to see that an old man in his eighties is able to ward off a crowd. When standing, it’s like a poised scale. When acting, it is as agile as the running cartwheel. Tipping to one side causes falling, double weighting causes stagnation. Those who ignore the flaw of double weighting will fail to master the skill and will be subdued by others. To avoid this, one must comprehend yin and yang: ‘sticking to’ comprises ‘going along with’, and ‘going along with’ comprises ‘sticking to". Yin does not leave yang, and yang does not leave yin: mastery of strength is based on their mutual complementary. Once attained, the more you practice mastery of strength, the better will be your skill; study and think silently until you can do anything at will. Following your opponent without your own initiative is to make the mistake of forgetting what is at hand and instead seeking far and wide. A tiny mistake, but one that may go wrong by a thousand miles. Beginners should bear this in mind.
Long-Chuan, which denotes the serial forms, is like the flow of water in a great river or sea, running without end. The thirteen kinetic movements are: pung (warding), lu (diverting), ji (pressing), an (pushing), tsai (plucking), Ii (twisting), zhou (elbowing) and koa (leaning). These are connected with the eight trigrams, and jin (stepping forward), tui (stepping backward), ku (looking to the left), pan (looking to the right) and zhong-din (central equilibrium), which coincide with the five elements ─ metal, wood, water, fire, and earth. Pung, lu, ji, and an are called the four straight direction manipulations toward south, west, east and north, respectively. Tsai, li, zhou, and koa are the four diagonal manipulations toward the four comers of northwest, southeast, northeast and southwest, respectively.
Original annotation: the work of late Chang San-feng of Mt. Wu-Dang, who wanted the ‘heroes’ in the world to prolong life, not solely for martial arts.

Key to the Thirteen Kinetic Movements
When the mind controls the operation of chi, calmness and steadiness are of decisive importance. Only then can the chi be capable of permeating the bones. When the chi directs, the movements of the body must comply with the chi. Everything should be done according to the dictates of the mind. ‘Suspending the top of the head’ has the effect of promoting one's spirit and preventing the body being heavy and clumsy.
The interaction of the ideas and chi should be made with alacrity; only then can you enjoy the facility of the movements, i.e. changing of empty and solid. Alacrity comes with learning to breathe well. When attacking, exerting strength must be concentrated, clear-cut and aimed in one direction. When standing, the body must be centred, straight, comfortable, and at ease as if it were supported from all sides.
The mobilizing of chi is like passing through a zig-zag hole of a pearl, reaching any part of the body. The exerting strength is like refined steel, able to destroy any hardness. The posture is like that of a hawk seizing a rabbit. The spirit is like a cat about to catch a mouse. In stillness, it is like that of a mountain range. Motion is like that of the torrent flowing in the river. Storing up energy is like that of an open arrow. Exerting strength is like letting an arrow go. Seek the straight in a curve, preserving the strength before releasing. The steps should follow the body’s movements. The strength issues from the spine. To withdraw is to advance. Although the strength appears broken, the movement has continuity. When moving backwards and forwards, the exerting strength should contain folds. When advancing and retreating, there must be alternating of empty and solid in the steps. Extreme softness leads to extreme hardness.
The chi which is cultivated without hindrance will be free from side effects. The strength that is stored in a curve is always abundant. The mind is the first commander, the chi is the banner, and the waist is the axle. First, learn to stretch and expand, then to tighten and condense; then it will be possible to be perfectly integrated.
‘First conceive in your mind, then express in the body’. Keep the abdomen loose, and the chi permeates the bones. Give the spirit free rein and the body will be calm. Be attentive at all times. Always remember that one single movement suffices to effect the whole body’s movement; there is no isolated stillness without the enveloping of the whole being.
In all movements the chi adheres to the spine and permeates the bones. Inside, one is firm; outside one shows peacefulness. The even pace is like a cat’s walking. The strength exerted is like pulling silk from a cocoon. One's attention is on the spirit, not on the chi. Too much preoccupation with chi results in stagnation. Chi is effortless in motion, but the strength exerted without chi results only in ‘simple hardness’. The chi is like the cartwheel, and the waist is the axle.

The Treatise of Taichichuan
At the start of any movement, all parts of the body are called on to move and act with agility, i.e. they are functionally and sequentially linked throughout the body. The chi should be stirring, and the vital force is concentrated inwardly. There should be no deficiency or pitfalls; neither concavity nor convexity; no disconnection or extension.
The strength is rooted in the feet, bursts out in the legs, is dominated by the waist, and exhibited in the fingers. Only when the feet, the legs, and the waist are organized as a functional integrity are you then able to catch the optimum moment and the advantageous position whenever you are confronted with an opponent. If you fail in holding the advantage, your body will be in disorder, and your strength will be dispersed.

The source of this distortion should be sought from in the waist and legs, whether at the top or below, in the front or behind, to the left or right. Use the mind, not any outward forms. If there is something at the top, there must be something below; if there is something in front, there must be something behind; if there is something in the left, there must be something in the right. Like pulling a tree out of the earth, it is much easier if the root is shaken and loosened first. The changing of solid and void must be distinct. There is solid and empty in any movement, and any movement consists of void (empty) and solid. The chi and strength are linked throughout the body without interruption.

The Song of the Strike-Hands (Tuishou)
Warding, diverting, pressing and pushing, are always done with seriousness and caution, with all parts of the body coordinated. This protects you from any invasion by an opponent: let one strike with all their might.
Four ounces can deflect a thousand pounds. Divert the oncoming force into emptiness, attack when the forces join.
Sticking, connecting, adhering, and following. Do not lose contact and do not resist.
‘If my opponent doesn't move, neither do I. If he starts to move, I move beforehand. The strength appears loose, but it is not so. It is ready to exert, but it doesn't appear. Even if the strength appears broken, the sense of continuity remains.’

Chant of the Thirteen Kinetic Movements
Never neglect any of the thirteen kinetic movements or that the waist is the source of sense and perception. Be attentive to the alternation of empty and solid.The chi moves throughout the body without stagnating. There is movement in stillness, and stillness in movement.Miracles evolve during competition. Every posture is the creation of your will. Relax the abdomen but put the chi in full swing, with the coccyx centred, and the spirit rising up.The body should be light and agile with the top of the head suspended. Carefully study the means of opening and closing, bending and stretching; these are done with effortlessness and in freedom.Fundamentals and guidance should be made through oral teaching while skill is gained by self-study and continuing practice.What is meant by making good use of the ‘body’ and its function?
‘It is the guidance of spirit-mind which is the master, and the bones and flesh which are the servant’.
Think what the final purpose is, it is ‘longevity with eternal spring’.
Use your time and effort well ─ seek in this direction.