The core meditation practice of non-dual tantric yoga, the "Gesture of Wonder" (vismaya-mudra) or "Divine Gesture" (shambhavi-mudra) :
sampradāyam imam devi śṛṇu samyag vadāmy aham |
kaivalyaṃ jāyate sadyo netrayoḥ stabdhamātrayoḥ || 113 ||
"O Goddess, listen !
I will tell you that true tradition :
liberation arises at once
simply from keeping the eyes unmoving."
saṃkocaṃ karṇayoḥ kṛtvā hy adhodvāre tathaiva ca |
anackam ahalaṃ dhyāyan viśed brahma sanātanam || 114 ||
"Having closed one's ears
and contracted the anus,
meditate the (inner sound) without vowels or consonnants.
One will enter the Ever-Expanding One, the Primordial One."