Yoga is the cessation of the fluctuations of the mind stuff
Yoga is the union of the Atma with Paratma, of the Self with the Overself, the religionist will call it union of the soul with the Lord. So many variances of ultimately the same process, a merging of the individuality with the Cosmic.
Just as Ayurveda is the Science of Life, Yoga is the Science of the Spirit. Just as Ayurveda teaches us that we are one with Nature and going contrary to Her rules leads to disease (or dis-ease, falling out of harmony with Her principles) likewise Yoga teaches us that we are one with Spirit (God, Brahman, Allah, Shiva or by whatever name one designate that Ultimate Transcendental Truth) and both forgetting this (called Avidya or ignorance of our True Soul Nature as Children of the Most High) and going contrary to Cosmic Laws brings suffering to ourselves and others.
In this verse, which is my favorite and most repeated verse to my students, Patanjali provides a definition of how Yoga or union with the Absolute, the One Without a Second, can be achieved : by the cessation of the fluctuations of the mind stuff.
The mind is usually fixated in 3 dimensions: the past, the allurement of the senses—the now distractions, and anticipation—the future (usually in association with lust and fear). The mind is rarely at peace with itself and usually only cognizant of the ripples, the modifications, the fluctuations (vrittis) it creates and leaves in its own awareness. The mind is both hypnotized externally by the world and internally by its own indigestion, programming and constant inner dialogue (self-hypnosis). Should the ripples stop, the mind would become a lake, perfectly still: ‘Be still and know that I am God” is indeed sage advice as anything else is rightly a definition of madness, of missing the mark, of forgetting our True Soul Nature, which is the mother of all sin—or self inflicted non-sense or self inflicted negation of the Truth whether by external agents through their own agenda or ignorance or through our own created veils. Hence the importance of Meditation which simplified is: Sit down (in a sit up position)—Be Still—and Shut up (both literally and figuratively meaning both the outer and inner dialogue).
There is something I would like you to remember and it is this: A still mind is a mind at peace as well as a sharper mind. A quieter mind is a more aware mind and with increased awareness comes more control of what you allow to feed your mind both externally and internally. A more aware mind that has more control of its own thought processes is the road to mastery of self and life, and one less subject to the influence of others. And it all starts with AWARENESS.
If you don’t already have one, create a sacred space where you will not be disturbed and if possible use this same space and spot for your meditation practices where nothing else happens but your Sadhana (spiritual practice). Make your spiritual practice a habit by dedicating the same time(s) every day to it at your sacred space. Dedicate a minimum of 20 minutes a sitting to the following Awareness Meditation, ideally once in the morning after showering and once in the evening either before dinner or bedtime. But if you can only manage once a day (at the same time every day), you will still benefit from this simple but profound exercise.
a) Make sure you wear loose fitting clothing and are relaxed. Either sit down on a cushion on the floor in a comfortable cross-legged position or on a chair with hands on top of your lap, legs uncrossed with feet flat on the ground. Ensure your back is straight but not stiff.
b) Scan your body from head to toe, gently releasing any tension. Just gently tell your body to let go of any tension, to relax. Feel all tensions, physical and mental, melting away. Spend a few minutes doing this and where necessary making physical adjustments to ensure you are comfortable.
c) Next bring your awareness to your breath. Do not control it. Just become aware of it. Become aware of how your natural breath enters and exits your nostrils. That is all—just witness the breath.
d) Should any thoughts or other internal or external distractions distract you from witnessing the natural flow of your breath (which undoubtedly will happen!), simply and gently bring your awareness back to witnessing the breath. Do not offer resistance to the internal or external distraction, do not fight it but also do not get drawn by it—simply gently bring your awareness back to the breath.
e) You may find the following analogy useful. See every thought as simply passing on the space of your Consciousness just like a cloud does upon the space of the vast blue sky, eventually dissipating to simply reveal more of the blue sky, the spaciousness of Consciousness itself (the veils having been lifted).