In Dharana 13 of Vigyana Bhairava Tantra, Shiva says:
Hands blocking entrances in all directions
Piercing the ajna to see the light
Be absorbed and realize Shiva
I acknowledge this graphic of Shanmukhi mudra from the Net.
I went through the Hatha Yoga Pradipika by Yogi Svatamarama, considered the authoritative text on asanas, pranayama, mudras etc. Svatamarama talks about 84 asanas handed down from Shiva. However, i couldn’t find a mention of the shanmukhi mudra in this text from 15th Century CE.
This dharana is a powerful technique to perfect pratyahara, controlling the senses and depriving the mind of sensory inputs.
The two index fingers rest lightly on eyelids closing them.
The two middle fingers rest on the side of the nostrils controlling breath.
The two ring fingers rest on upper lips and
the two little fingers rest on the lower lips closing the mouth.
The two thumbs rest lightly on the inner ear lobes closing the ears.
Be careful when you practise this mudra. Excess pressure on the eyes will make you see stars. Excess pressure on the ear lobes will create strange inner sounds. Excess pressure on the nostrils will have you gasping for breath.
That’s not the purpose of this mudra. It’s to gently restrain the senses. The mental effort is important, not the physical.
Swami Sivananda of Divine Light Foundation and later his disciple Swami Satyananda of Bihar School of Yoga talk about nada yoga in relation to this mudra. Gentle pressure on ear lobes creates an inner vibration. With focus on this sound one can travel inwards. Similarly, gentle pressure on the eyelids leads to an awareness of the bindu, the point at the back of the head, where traditionally brahmins leave a tuft of hair after shaving their heads.
Swami Satyasnagananda Saraswati of Bihar School of Yoga, and author of Ascent, an excellent commentary on Vigyana Bhairava Tantra, says that this mudra creates energy that pierces the ajna chakra and leads to the bindu, which is the point between psychic and spiritual wisdom.
With the awareness of the bindu, one journeys to Shiva at the Sahasrara.
This mudra is traditionally practised in the padmasana or siddhasana postures.
Scholars say that in these 112 dharanas given by Shiva to Shakti, there is one technique for each of us to become aware of Shiva and realize him. This is why these dharanas cover every sensory organ and action.