(i.e., recaka, p[u.bar]raka, and kumbhaka), which, according to the following verses, cannot be achieved through force (hath[a.bar]t): "In the first stage of [reciting the syllable ] om, this state [of recaka in which pr[a.bar]na has been expelled from the body] arose at will [and] not through [any] force at all.
The chapters on p[a.bar]supatayoga mention various [a.bar]sana (svastika, padmaka, bhadra, simha, and kacchapa), a fourfold pr[a.bar]n[a.bar]y[a.bar]ma, a Yoga with six auxiliaries, as well as some of the terminology of medieval Hathayoga, such as moving v[a.bar]yu through n[a.bar]dis, kumbhaka, and some allusions to practices resembling the Hathayogic mudr[a.bar]s, such as fixing the tongue on the palate (t[a.bar]lau jihv[a.bar]m sam[a.bar]dh[a.bar]ya) and locking the navel (n[a.bar]bh[i.bar]bandhana).
(146.) For example, in explaining pr[a.bar]n[a.bar]y[a.bar]ma, the terminology used in the Datt[a.bar]treyayogas[a.bar]stra is tantric: i.e., recaka, p[u.bar]raka, and kumbhaka (e.g., 68).
When we look more closely at specific practices such as khecarT mudra and kevala kumbhaka we see evidence to support the argument that within hathayoga tradition the convergence between liberation and optimum physical and mental health is completely natural and interdependent.
With the assistance of advanced hathayoga techniques including sakticalana mudra, khecarT mudra, vajrolT mudra, sumbhavT mudra, mula bandha, jalandhara bandha, and kevala kumbhaka, the sadhaka (practitioner) attempts to stimulate, harness, and unite the flow of vital energy from the left and right channels at the brahmadvara (gate of brahma) and raise it (utthd) forcefully (hafha) through the central channel and the six primary cakras (wheels or circles of energy) into the cranial vault located in the crown of the head (sahasrara cakrd).
By emptying the flow of subtle energy from the peripheral channels into the central channel (also called sunyata nadi) and guiding it upwards into the crown cakra via a series of advanced practices including khecari mudra and kevala kumbhaka, the adept yogin or yogini becomes aware of deeper and more penetrating levels of consciousness and witnesses (or visualizes) the progressive transformation of the material body (sarira) into an immortal or divine body (divya deha).
For this reason it is important to examine the logic of hathayoga sadhana in some detail in order to understand how advanced, esoteric practices such as khecari mudra and kevala kumbhaka guide the adept toward a direct experience of substantive non-duality--defined in my argument as both liberation and immortality.
It is particularly evident that through disciplined and sustained practice and by the sheer force of prana or kundalini generated during preliminary exercises, particularly in the lower cakras, more advanced practices such as khecari mudra and kevala kumbhaka arise spontaneously in the adept stages of yoga sadhanu.
The twelfth-century commentator, Dalhana defines pranayama as "suppression of wind" (vayor nirodhah) and explains: "Although pranayama is threefold on account of its divisions of recaka, puraka, and kumbhaka