Hatha Yoga Pradipika, ch.3 , v.5
During yoga practice certain hand position- referred to as mudras - are often adopted. The word mudra can be translated as 'seal', meaning knowledge. Mudras are subtle physical movements that increase awareness and concentration. There are many different types of mudra in the yogic scriptures, some of which involve the whole body, while others are simple hand gestures. Generally mudras are said to manipulate prana, or energy flow, in the body. Hand mudras are meditation tools, which redirect the energy emitted through the hands back in the body.
The Chin Mudra is a classic yogic meditation posture and is he gesture of consciousness. The palms of the hands face upwards while resting on the knees, and the tips of the thumps and thumbs and index fingers touch, while the remaining fingers are relaxed and slightly apart. The thumb- and finger tips contain many nerve endings, and when they they create a circuit that send energy back to the body. A variation of this is the Jnana Mudra, which is the gesture of knowledge. It has the same finger position, but the palms point downward rather than upward.
Bhairava Mudras, meaning 'fierce gesture' is another mudra that you can assume during meditation. Sit in a comfortable cross-legged position and place your right hand on top of your left palm with the thumbs touching. Both hands then rest in your lap. The two hands represent the ida and pingala nadis*, symbolizing the union of the individual with higher awareness.
*There is a vast network of subtle energy channels, known as nadis ( meaning 'flow'), that criss-cross the entire body.These are the pingala nadi, the ida nadi, and the sushimna nadi, which form the prime conduits of energy throughout the system. One of the nadis ( the pingala ) is positive, one ( the ida) is negative, and the other ( the sushumna ) is neutral- just as in any electrical circuit.