Retire into solitude. Seat yourself on a clean spot and in erect posture, with the head and neck in a straight line. Be indifferent to the world. Control all the sense organs. Bow down in devotion to your Guru. Then enter the lotus of the heart, and there meditate on the presence of Brahman – the pure, the blissful…
The mind may be compared to a firestick, the syllable OM to another. Rub the two sticks together by repeating the sacred syllable and meditating on Brahman, and the flame of knowledge will be kindled in your heart and all impurities will be burnt away.
Kaivalya Upanishad
Yoga Prescribed 