Chapter 6 of 23 · Kailasa Samhita · Overall chapter 371 of 464
Description of Nyasa
Shiva details the nyasa procedure - ritually assigning mantric syllables and corresponding divine forms to specific points on the practitioner's own body - as the technique by which Surya's worship, and ultimately Shiva's own thirty-eight-part form, become internalised within the sannyasi.
Ishvara said
A tiger hide is spread south of the mandala, sprinkled with pure water while reciting the weapon mantra, with Pranava first and ending with the foundation mantra. Then the Shaktikamala mantra is recited in the dative, ending in "Namah". After chanting these he sits facing north, does breath-control with Pranava first, smears himself with ash with the Agni and other mantras, bows his head to the illustrious guru and draws a mandala again, with a triangle, circle and square on the outside. Chanting AUM and the foundation mantra he worships and sets up a conch shell, fills it with pure fragrant water with Pranava, and worships it seven times with perfumes, flowers and other things. After the mantras he shows the cow and conch gestures and, with the weapon mantra, sprinkles water on himself and on the perfumes, flowers and other worship materials. After three breath-controls he names the rishis: for the mantra to the illustrious Surya the rishi is Devabhaga, the metre gayatri and the deity Surya is Maheshvara himself. Uttering "Hram" and the rest he places the deities on six parts of the body. By the rules, starting from the first, he worships Prabhuta, Vimala, Sara and so on. Then he worships Rudra as the fire of destruction, Shakti as the support, Ananta, Prithivi, Ratnadvipa, a grove of wish-trees, a jewelled house, the red pedestal at the feet, the four deities of dharma, knowledge, non-attachment and prosperity starting from the east, the deities of adharma at corners like Agni, the lower lip of maya and upper lip of learning, sattva, rajas and tamas, the directions from the east, and in the centre Dipta, Sukshma, Jaya, Bhadra, Vibhuti, Vimala, Amogha, Vaidutya, Sarvatomukha, Kandanala, Sushira and Tantukantaka, then the root and filament that light all selves, the five-jointed pericarp, petals and filaments, and Brahma, Vishnu, Rudra and the supreme self. He worships the supreme self within his own self, and knowledge as the supreme self, and then the yoga pedestal called Surya. One who knows the foundation thinks of the embodied foundation seated atop the pedestal. Seated, he controls his breath and thinks of that foundation as his own root, raising potency, energy and power through the pingala channel. Bright inside the inner mandala, it emerges like an offering of flowers. Shiva appears, red as vermilion, his beloved forming the left half of his body, wearing rudraksha and holding a khatvanga, a skull, a goad, a lotus, a conch and a discus, with four faces and twelve eyes, radiant, emerging from the lotus in his heart.
Then he first chants Pranava and recites "Hram Hrim Sah," invoking Martanda's brightness and potency: I bow to you and perform the invocation. Saying this he shows the gestures for invoking and installing, and with "Hram Hrim Hrum" places the mantra in the limbs. Maheshvari, he visualises five offerings and worships the stem, filaments and six parts of the lotus three times. As a second sheath around it an intelligent person worships four images in the directions of Agni, Ishana, Nirriti and Vayu; Parvati, from east to north, Aditya, Bhaskara, Bhanu and Ravi are worshipped at the roots of the petals; as a third sheath, from Ishana onward, Arka, Brahma, Rudra and Vishnu again, and from the east Soma, Kuja, Budha, Jiva, Kavi, Manda and dark Tama in all directions. Alternatively the twelve Adityas can be worshipped as the second sheath and the twelve zodiac signs as the third. All around on the outside the seven oceans and seven Gangas are worshipped, then rishis, gods, gandharvas, serpents, apsaras, village deities, yakshas, demons, the seven metres as horses and the valakhilyas. So the divinity Divakara is worshipped with three sheaths, and the mandala with its squares drawn. Then he places on its stand a copper vessel that holds a prastha of water, filled with pure water scented with flowers and other things. Kneeling on the ground he worships it with perfumes and flowers and lifts the arghya vessel to eyebrow level. Then he recites the savitri mantra that grants every siddhi and bestows enjoyment and liberation: vermilion-coloured one with the excellent disc, wearer of diamonds, lotus-eyed, excellent lotus, cause behind Brahma, Indra and Narayana, I offer you red powder, golden water, garlands, kumkuma, excellent kusha and flowers with a golden vessel, this wide arghya; illustrious one, be pleased. So saying he offers the arghya to Surya's image.
Controlling himself, bowing, he then says: I bow to Shiva, the original cause, with Amba and his ganas, and to the three divinities Brahma, Vishnu and Rudra. He bows and sits on his seat, names the rishis again, cleans his hands with water and applies ash again as before. He places the mantras on himself to increase his devotion to Shiva. A learned person with five offerings bows to the illustrious guru and then bows to Pranava in the dative. With bindu and sound as the fifth, Pranava has five parts; it is also said without bindu and sound, but this lord of mantras should be recited with bindu and the five parts, being complete only so. After chanting the seed mantras in order he bows to the guru and to Ganapati, placed on the two arms and thighs, and standing with joined hands bows to Durga and Kshetrapala. He chants "AUM astraya phat" six times and washes his hands in turn, then the apasarpantu mantra followed by Pranava, and, saying "astraya phat," claps three times. To remove obstacles he raises his hands and claps three times again and glances at the beings in the sky. Seated, he restrains his breath and remembers the hamsa mantra, and through the brahma channel invokes the living consciousness in his heart. He meditates on Parameshvara's form as consciousness inside a lunar-disc-shaped consciousness inside the thousand-petalled lotus, beyond the twelve-petalled. In order he does the three breath phases sixteen, sixty-four and thirty-two times, letting the breath dry, burn and leap up. Following the Vedas and other texts he uses breath-control through wind, fire, water and the others and raises the kundalini from muladhara to Brahmarandhra. When it is brought up, supreme amrita begins to flow inside the lunar-disc-shaped consciousness, and when the body is sprinkled with it the body is purified and filled with excellent feelings. The sense of "Soham" descends within his own self, in the heart lotus, and by the flow of amrita the individual self enters the supreme. So, self-controlled, he establishes the breath properly.
Single-minded, the yogi thinks of the Matrikas and, uttering Pranava, places them externally. He restrains his breath again as taught, free of jealousy and engaged in renunciation, and remembers Shankara in his heart. Devi, the rishi of Pranava is Brahma, the metre gayatri and I, Sadashiva, the supreme self, am the deity. A is the seed, U the Shakti and M the pin used for liberation. From the thumbs to the base of the palms the hands are cleaned and the hand-placing done after AUM, in order from the right thumb to the left little finger. He places A, U and M with bindu in the heart and other places, ending with "namah". Reciting Aumkara first he invokes brahman in his self. For the heart and the rest he says "in this limb" and ends with "namah". With the sound U the placing of Vishnu is done on the head, with M the placing of Rudra on the tuft; so the sage forms a mantra-armour in the eyes and head. When this is done the mind must be attentive. Brahma's five portions are placed on face and digits, Ishana's five in five places, head, face, heart, private parts and feet, Purusha's four in the face, Aghora's eight in heart, neck, shoulders, navel, sides, back and chest, Vamadeva's thirteen in anus, organ, thighs, knees, calves, buttocks, waist and sides, and Sadya's eight in the eyes. Those who know placement do this with the portions in feet, hands, breath, head and arms. All thirty-eight portions must be placed. After this an intelligent person chants Pranava and places it in the two arms, elbows, wrists, sides, stomach, calves, feet and back, which is called hamsa-placement and kindles understanding of the supreme self.
Retold in our own words from Bibek Debroy's English translation of the Shiva Purana (Penguin Classics). Names, numbers and the order of events follow the source.