Qi in the Daodejing—The Way and its Power 
Compiled from various sources with commentary by John Voigt
The Daodejing (Tao Te Ching) is a book of slightly over 5,000 Chinese words said to have been written by Laozi (Lao Tzu) in the sixth century BCE. It is a collection of 81 poetic aphorisms that offer a spiritual as well as practical way to live in the world. It is the most widely known and influential book ever written in Chinese.
Qi (chi or ch'i) is a Chinese concept open to many interpretations. It is a relative term, a propositional term, gaining its meaning by the context in which it appears. Within Daoism it may refer to a hidden spiritual creative force that gives birth to all that is, was, and will be. It is the vital life force gained by the act of breathing, and thereby the breath itself. All of life and existence are manifestations of qi. Also in everyday speech, manifestations of qi are customarily called qi: For example, excessive fire qi in the liver may cause anger, but this anger itself is called "qi." A qi master may have students rub their hands together to generate qi, but the heat that is felt as a result of this is itself sometimes called "qi."
Part of the Guodian Laozi, the earliest known copy of the Daodejing, circa 300 BCE. www.edepot.com
In the Daodejing, the word qi appears three times, in chapters 10, 42, and 55
Chapter 10 - Meditating and Living the Life Force
Carrying the body and soul and embracing the unity of the One,
Can you be without separation?
By gently focusing on the breath (Qi),
Can you be like a peaceful infant?
By cleansing and purifying your inner vision,
Can you be without a blemish?
Seeing clearly in all four directions,
Can you remain detached and inactive?
Opening and closing the gates of heaven,
Can you receive passively as does a woman?
Give birth and nourish, but do not possess.
Move forward without any expectations.
Be not a demanding ruler (they often slaughter and cheat).
But without words love people and heal the kingdom.
This is called the walking the path of the De, (the virtuous inner strength of the life force).
Chapter 42 (excerpt) - Genesis
(Before the beginning was)
Dao from which is born One (the unmanifested Qi).
One which gives birth to Two (the static polarities of Yin and Yang). Three—a dynamic Qi appears opening Yin and Yang into a harmony of interaction.
And from Three, creation [in time and space] unfolds and all things are born.
In this way, all things carry yin on their backs and embrace yang.
By blending the qi they achieve harmony.
Chapter 55 - Appearances of the Mysterious Life Force
Possessing De [abundant Life Force] like a naked baby,
Wasps, scorpions, serpents, beasts, or birds of prey will not sting, bite or attack.
Bones are delicate, muscles soft, but firm is the grasp of the hand.
Knowing nothing of the sexual union of female and male, yet full of Jing [the Essence of life] the boy baby's penis becomes erect.
So perfect is the infant's natural harmony [with the Dao],
He can cry all day and not becoming hoarse.
Harmony—Eternal—Enlightenment. A long life of Good Fortune.
When the mind and heart concentrate (too strongly) on qi [the breath of vital energy], this is called 'forcing things to attain strength.'
But such violent breath work is contrary to the Dao.
And with gaining such 'strength' the person soon grows old and dies.
Laozi, Chinese philosopher and mystic, founder of Daoism
Chapter titles were added by Qi Encyclopedia and are not found in the original texts.
Dao (Tao) means the "Way." The second word of the title, De, means "Virtue"—but it strongly implies the inner strength and power needed to obtain virtue. Such major translators as Edmund Ryden define De as "Life Force." Since life force is a commonly used definition of Qi, we have a theoretically possible title of The Way of Qi or even more fancifully The Tao of Ch'i.
What is qi in the Daodejing? Immediately "breath"—and although focused gentle breathing gymnastics may lead to the experiencing of the Dao—qi is not just inhaling and exhaling air.
And it is not simply "energy" or even the source of energy, but rather that which emanates from the Dao, then through its negative and positive (yin and yang) spiraling interactions becomes all physical, conscious and spiritual things and their energetic movements.
The Daodejing opens with The Dao that can be told is not the eternal Dao. The name that can be named is not the eternal name. The word eternal Dao is not to be defined. Likewise practicing masters of the Chinese energy arts often stay away from defining Qi—or to keep pesky students off their back, simply smile and tell them, energy. Nevertheless, there is an intriguing possibly that can be explored: Dao is Qi—Qi is Dao. 
Various forms of the title. The title appears as Daodejing, Dao De Jing, or Tao Te Ching. Originally it was called the Laozi or Lao Tzu, after its legendary author. Dao means "Way" or "Path to spiritual enlightenment." A common English translation is The Way and its Virtue [or] Power. The Jing in the title means "Book," "Classic," or "Scripture."
 ^ Yin/Yang.
Yang originally meant what was on the sunny side of a mountain; yin meant what was on the dark cold moonlit side of the mountain. Never static, as the day progresses each continually moves back and forth with the other. So by extension we have light-positive-masculine qi and dark-negative-female qi (no value judgment is implied).
It makes no sense to probe into what was before the Dao, for there was no time and no physical reality. Dao as archetypal Mother gave birth to the One, its alter-image, the Hidden Qi: the potential for time, space and consciousness to exist. From the One appeared Two, separate and non-interacting Yin and Yang—there is no movement and so there is no nothing to be seen.
From Two came Three, the Qi generating interaction and movement between the previously static yin and yang. And so came into being all the physical and energetic things and the consciousness that makes the mind and life possible throughout the entire universe.
When this emanating process is in harmony, that is to say properly balanced, all is as it should be, and a man, woman, and even especially an infant can be with the Dao. When disharmony happens (as in much of our modern civilization) a harmful damaging chaos is often manifested. Things are no longer with the Dao. [John Voigt].
Henry Zhuang: Non-being is the state before the existence of heaven and earth. The unvarying name is non-being, which is the essence of Dao; but how can nihility become being? It can by using, distributing, and generating qi, and using qi to give birth to things, it becomes heaven and earth; thus qi is the origin of being. Therefore, Lao Tzu explained: "The Dao gives birth to the one, which is taiji." Taiji is the one, the qi. It is this originating qi that breeds yin qi and yang qi. The two qi interact with each other to give birth to all. http://ymaa.com.
also see: Elizabeth Reninger. "Taoist Cosmology."
Concentrate. In Chapter 10 and in Chapter 55 the reader is told about concentrating on breathing qi-vital energy. But two kinds of concentrating are meant, with two kinds results taking place. Chapter 10 says to softly and gently concentrate (meditatively) on breathing like a new born baby to gain the peace and harmony of the Dao. But if we force the breathing with too much conscious forceful effort, Chapter 55 gives us: All devices for inflaming life, And increasing the vital Breath, by mental effort are evil and factitious. Things become strong, then age. This is in discord with the Dao, And what is not at one with the Dao soon comes to an end. (translation by English occultist, Aleister Crowley). http://www.mobilewords.pro
The original meaning of the word dao is a path along which a traveler walks; then came the related ideas of "the direction," "the way. Then: principle/truth/morality/reason/skill/method/the Dao (of Daoism)/steps in a process. http://www.mdbg.net
For more on the idea that Dao is Qi—and Qi is Dao, see Ken Rose. "What Is Qi?"
Typing "dao is qi" on a Google search retrieved this: http://www.google.com
"Dao De Jing." New World Encyclopedia.
The Feminine Tao.
Michael P. Garofalo. Tao Te Ching (Dao De Jing).
Michael P. Garofalo. Translators Index. Index to Tao Te Ching (Dao De Jing) Online and In Print... Egreenway.com.
Robert G. Henricks. Lao-Tzu Te-Tao Ching. Ballantine Books, 1989.
Hymning the Tao Te Ching/Daodejing—word-by-word Chinese-English Study Version. www.earlywomenmasters.net
[This outstanding site was often consulted; however any perceived mistakes in my translation are my fault—John Voigt.]
Michael LaFargue. The Tao of the Tao Te Ching. SUNY Press, 1992.
"Laozi," by Roger T. Ames. Encyclopaedia Britannica.
"Laozi." New World Encyclopedia.
Laozi. Daode Jing/ Lao Tzu. Tao Te Ching; Tim Chilcott, translator.
Derek Lin. Das Tao Te King von Lao Tse. [text in English].
JeeLoo Liu, Douglas L. Berger. Nothingness in Asian Philosophy, p.183. Routledge, 2014.
"Tao Te Ching." Wikipedia.com
"Tao Te Ching: Literature." http://www.taoistic.com
Tao Te Ching: Sixty Interactive Translations.
Das Tao Te King von Lao Tse.
Terebess Asia Online (Tao). The Tao Te Ching by Lao Tzu. [125 translations]