The use of right hand in tantra for developing divine emotions or ‘devata bhava’ is known as Karanyasa. It is a kind of nyasa in which the bodily parts are touched by the right hand (kara) one by one and the names of the gods and goddesses are called, announcing that “I put the power of this particular deity into this particular part of the body.”
In Fetkarini Tantra (III.30-32) three varieties of nyasa are mentioned and karanyasa is said to be the most important among them. It is said in Agamarahasya (x.2) that “one who does nyasa regularly makes his body an abode of the God or Goddess one is worshiping”. Thus it may be said that the essence of karanyasa is to infuse in the body the energy or super power of the divine entity.
Nyasa is always performed after purifying the body by doing bhuta shuddhi – purification of the five elements, which together constitute the body, namely prithvi tattva, jala tattva, teja tattva, vayu tattva and akasha.
The five bhootas are said to reside in the body, e.g., the prithvi tattva in the lower limbs, jala tattva in the lower abdomen, teja tattva around the navel, vayu tattva in the thoracic cavity and akasha tattva in the head.
In Agamarahasya (X.9-13), bhuta shuddhi is described as purifying the elements forming the body, by smearing it with ashes, sprinkling it with water, and by reciting mantras and doing pranayama.