During meditation, care must be taken to keep the back straight and steady without bending forward or backward or sideward. If you bend or move, misdirection of highly potent energy (Kundalini) can occur resulting in mental derangement. Also wear loose clothes. Your eyes must concentrate on the tip of the nose. They must be half-open, so you are neither distracted nor falling asleep. Free your mind from bad thoughts and fill it with sacred ones. To achieve this, you must control your senses. Your ears must be trained to listen only to noble and elevating ideas, and to eschew evil speech and gossip. Your eyes must be tuned to see the Divine. The restless mind must be restrained by making it concentrate on inhalation and exhalation while incessantly repeating the Mantra, ‘So-Ham’ (I am He). Through these postures and activities, your life-breath is controlled and this will ensure that the great power of Yoga is revealed unto you.