History of yoga

yoga Sutras of Patanjali

Atha Yoganusasanam / 1.1
Now, the exposition on Yoga.
Yogas citta-vritti-nirodhah / 1.2
Yoga is the stilling of the fluctuations of the mind.
Tada drastuh svarupe vasthanam / 1.3
Then, the Seer abides in its own nature.
Vrtti-sarupyam itatatra / 1.4
Otherwise ( the Seer) identifies with the fluctuations ( of the mind).
Bhagavad Gita

Know the self as a rider in a chariot, and the body, as simply the chariot.
Know the intellect as the charioteer, and the mind, as simply the reins.
The senses, they say, are the horses, and sense objects are the paths around them;
He who is linked to the body ( atman), senses, and mind, the wise proclaim as the one who enjoys.
When the five perceptions are stilled, together with the mind, and not even reason bestirs itself; they call i the highest state.
When senses are firmly reined in, that is Yoga, so people think.
From distractions a man is then free, for Yoga is the coming-into-being, as well as the ceasing-to-be.
Kapha Upanishad 3.3-4 / 6.10-11 ( Olivelle, trans.)