Śivasaṃhitā 3.102

This verse describes the interior posture of siddhāsana: the gaze directed toward bhrūmadhya, the point between the eyebrows, while the body remains niścala, utterly still. This is not merely a postural instruction but a convergence of sensory restraint and directed awareness toward a precise focal point.

Bhrūmadhya designates the space between the eyebrows, seat of the ājñācakra in tantric subtle anatomy. Niścala (‘motionless’, from nis- + cal, to move) points to a stillness that transcends the physical. Saṃyatendriya (‘with senses controlled’, from saṃyata + indriya) evokes Patañjali’s fifth aṅga, pratyāhāra, the withdrawal of the senses from their objects.

The technique of fixing the gaze at bhrūmadhya—known as śāmbhavī mudrā in other texts—acts simultaneously on the nervous system and on concentration. Elevating the eyes toward that point stimulates the optic nerve in a way that facilitates interiorization. Practiced within siddhāsana, this visual orientation transforms the posture into a complete meditative instrument.