Vijnana Bhairava Tantra
51: If one fixes one's mind at dvadasanta again and again howsoever and wheresoever, the fluctuation of his mind will diminish and in a few days, he will acquire an extraordinary status.
52: One should contemplate that one's own body has been burnt by Kaalagni, arising, from the movement of time. Then at last one will experience tranquility.
53: In this way, if the aspirant imagines that the entire world is being burnt by the fire of Kalagni and does not allow his mind to wander away to anything else. then in such a person, the highest state of man appears.
54: If the yogi thinks deeply that the subtle and subtler constitutive principles of one's own body or of the world are being absorbed in their own respective causes, then at the end, para devi or the supreme goddess is revealed.
55: If pranasakti which is gross and thick, is made frail and subtle (by yogic discipline; particularly pranayama) and if a yogi meditates on such sakti either in dvadasanta or in the heart (the centre of the body) by entering mentally into it, he is liberated and he gains his natural sovereign power.