Sutras 31 and 32 of Book One of the Yoga Sutras of Patanjali
Sutra 1:31. (Mental) pain [dukha], despair [daurmanasya], nervousness [angamejayatva] and hard breathing [shvasa-prashvasa] are the symptoms of a distracted condition of mind [vikshepa-sahabhuvah].
Dukha is pain; suffering; misery; sorrow; grief; unhappiness; stress; that which is unsatisfactory. Daurmanasya is despair, depression etc., caused by mental sickness; feeling of wretchedness and miserableness. Angamejayatva is shaking of the body; lack of control over the body. Shvasa-prashvasa is hard breathing; inspiration and expiration.
These are the symptoms of a mental state that is outward-turned and impelled toward–and absorbed in–externalities.
Sutra 1:32. For removing these obstacles there (should be) constant practice of one truth or principle.
The meaning of this is so simple that most commentators miss it.
Yet both Vyasa and Shankara comment that it means the practice of meditation on the One, and continual awareness of the One outside of meditation. This will unify the mind which is the producer of the problems listed in the previous sutra when it becomes fragmented or scattered by being divided by sensory experience. The only cure for this is unifying the mind by means of meditation.
When practiced for a sufficient amount of time, the state of unity can be maintained in the mind even when dealing with the multiplicities of ordinary existence.
Need more specifics? Read these articles:
- Most importantly: Om Yoga at a Glance
- Then: Meditation as Training for Living
- Learning to Use Your Mind
Next in the Commentary on the Yoga Sutras: 7 Ways to Purify the Mind, Part 1
Previously: Om, the God-Word