The Yoga Sutras of Patanjali: Commentary on the Raja Yoga Sutras by Sri Swami Satchidananda
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The Yoga Sutras of Patanjali: Commentary on the Raja Yoga Sutras by Sri Swami Satchidananda

A sickly body can never be fit to sit; it will not allow the mind to meditate quietly. Weak nerves will always create tremors.
The great South Indian saint, Thirumular, said, “Where the mind goes, the prāṇa follows.”
The moment you understand yourself as the true Self, you find such peace and bliss that the impressions of the petty enjoyments you experienced before become as ordinary specks of light in front of the brilliant sun. You lose all interest in them permanently. That is the highest non-attachment.
In other words, Īśvara is all-knowing and is knowledge itself.
Who would not like serenity of mind always? Who would not like to be happy always? Everybody wants that. So Patañjali gives four keys: friendliness, compassion, delight and disregard.
In the fourth samādhi, even that ānanda is not there but just awareness of individuality. You contemplate the “I-ness.”
You have to always be at it, not just for a few minutes a day and then allowing the mind to have its own free time all the other hours.
“If you can control the rising of the mind into ripples, you will experience Yoga.”
“As the mind, so the person; bondage or liberation are in your own mind.” If you feel bound, you are bound. If you feel liberated, you are liberated. Things outside neither bind nor liberate you; only your attitude toward them does that.