A yogic technique
credited to Nathpanthi ascetics in their quest for bodily immortality via hatha
yoga practice.
The sun and moon are the most common metaphors used to
describe the process of achieving immortality in this way, with the sun
representing change and destruction and the moon representing stability and
immortality.
This union was sometimes depicted in extremely abstract
words, as a process in the subtle body, and other times in the most specific
manner conceivable, as in vajroli mudra.
This is urethral suction, sometimes known as the
"fountain-pen method," in which a man ejaculates into his female
partner and then pulls his semen, which has been refined by contact with the
woman's uterine blood, back into his body, along with some of his partner's
blood.
Despite the discomfort and denials of some commentators
(which are typical of most allusions to sexual activity as a component of Hindu
spiritual practice), the vajroli mudra is consistently identified as one of the
Nathpanthi activities.
More material may be found in George W. Briggs' Gorakhnath
and the Kanphata Yogis, published in 1982.
