This section is from the book "Mahanirvana Tantra (Tantra of the Great Liberation)", by Translated by Arthur Avalon (Sir John Woodroffe). Also available from Amazon: Mahanirvana Tantra: Tantra of the Great Liberation.
The father should place the son on his mother's lap, the mother sitting on her husband's left, and, after breathing the Varuna Vija ten times over the water, rub the hair of the boy's head with lukewarm water. He should then tie the hair with two blades of kusha grass into a knot, uttering meanwhile the Maya Vija (175-176). Then, saying the Maya and Lakshmi Vijas three times, he should cut off the knot with the steel razor and place it in the hands of the child's mother (177). The boy's mother should then take it with both hands and place it in the platter containing the cow-dung, and the father should then say to the barber: "Barber, do thou at thine ease proceed with the shaving of the boy's hair, Svaha." Then, looking at the barber, he should make three oblations to Prajapati, into Vahni, under his name of Satya (178-179). After the boy has been shaved by the barber he should be bathed and adorned with clothes and jewels, and placed near the fire on the left of his mother, and the father should, after performance of Svishti-krit Homa and the expiatory rites, offer the complete oblation (180-181). Then, uttering the following:
Hring, O Child! may the omnipresent Creator of the Universe grant thee well-being, he should pierce the ears of the boy with gold or silver needles (182). He should then sprinkle the child with water, uttering the
O Water! thou art, etc. (aforementioned); and, after performing Shanti Karma and other rites, and making presents, bring the ceremony to a close (183). The sacramental rites from Garbhadhana to Chudakarana are common to all castes. But for Shudras and Samanyas they must be performed without Mantras (184).
In the case of the birth of a daughter all castes are to perform the rites without Mantras. In the case of a daughter there is no Nishkramana (185).
I will now speak of the Sacred Thread Ceremony of the twice-born classes, by which the twice-born become qualified for performing rites relating to the Devas and Pitris (186).
In the eighth year from conception, or the eighth year after birth, the boy should be invested with the sacred thread. After the sixteenth year the son should not be invested, and one so invested is disqualified for all rites (187).
The learned man should, after finishing his daily duties, worship the five Devas, as also the Matrikas, Gauri, and others, and make the Vasudhara (188). He should thereafter perform Briddhi Shraddha for the satisfaction of the Devas and Pitris, and perform the rites, ending with Dhara Homa, as directed in the performance of Kushandika (189).
The boy should be given a little to eat; then his head, with the exception of the crown lock, should be shaved, and after that he should be well bathed and decked with jewels and silken clothes (190).
The boy should then be taken to the Chhaya-mandapa, near Fire, under his name of Samudbhava, and there made to sit on a clean seat to the left (of his father or Guru) (191). The Guru should say: "My son, dost thou adopt Brahma-charyya?" The disciple should say respectfully: "I do adopt it" (192). The Preceptor should then with a cheerful mind give two pieces of Kashaya cloth for the long life and strength of mind of the gentle boy (193). Then when the boy has put on the Kashaya cloth, he should, without speaking, give him a knotted girdle made of three strings of munja or kusha grass (194). On that the boy should say, "Hring, may this auspicious girdle prove propitious"; and, saying this, and putting it round his waist, let him sit in silence before the Guru (195).
This sacrificial thread is very sacred; Brihaspati of old wore it. Do thou wear this excellent white sacrificial thread which contributes to prolong life. May it be for thee strength and courage (196).
With this Mantra the boy should be given a sacrificial thread made of the skin of the black buck, as also a staff made of bamboo, or a branch of Khadira, Palasha, or Kshira trees (197). When the boy has put the sacred thread round his neck and holds the staff in his hand, the Guru should three times recite the
"O Water! thou art," etc. (aforementioned), preceded and followed by Hring, and should sprinkle the boy with water taken with kusha grass, and fill the joined palms of the latter with water (198). After the boy has offered the water to Suryya, the Guru should show the boy the Sun, and recite the
Mantra.
"Yonder is the Sun," etc. (aforementioned) (199).
After the boy has viewed the Sun, the Guru should address him as follows: "My Son! place thy mind on my observances. I bestow upon thee my disposition. Do thou follow the observances with an undivided mind. May my word contribute to thy well-being" (200). After saying this, the Guru, touching the boy's heart, should ask, "My Son! what is thy name?" and the boy should make reply: ", ., Sharmma, I bow to thee" (201). And to the question of the Guru, "Whose Brahma-chari art thou?" the disciple will reverently answer: "I am thy Brahma-chari" (202). The Guru should thereupon say: "Thou art the Brahma-chari of Indra, and Fire is thy Guru." Saying this, the good Guru should consign him to the protection of the Devas (203). "My Son! I give thee to Prajapati, to Savitri, to Varuna, to Prithivi, to the Vishva-devas, and to all the Devas. May they all ever protect thee" (204).
The boy should thereafter go round the sacrificial fire and the preceptor, keeping both upon his right, and then resume his own seat (205). The Guru, O Beloved! should then, with his disciple touching him, offer five oblations to Five Devas (206) -- namely, Prajapati, Shukra, Vishnu, Brahma, and Shiva (207). When the oblations are offered into Fire, under his name of Samud-bhava, the names of each of the Devas should be pronounced in the dative, preceded by Hring and followed by Svaha. Where there is no Mantra mentioned, this method is to be followed in all cases (208). After this, oblation should be offered to Durga, Mahalakshmi, Sundari, Bhuvaneshvari, Indra, and the other nine regents of the quarters, and Bhaskara and the eight planets (209). The name of each of these should be mentioned whilst the offering of oblations is made. The wise Guru should then cover the boy with cloth, and ask him, who is desirous of attaining Brahma-charyya: "What is the ashrama thou desirest, my son! and what is thy heart's desire?" (210). The disciple should thereupon hold the feet of the Preceptor, and, with a reverent mind, say: "First instruct me in Divine Knowledge, and then in that of the householder" (211).
O Shiva! when the disciple in this manner has thus beseeched his Guru, the latter should three times whisper into his disciple's right ear the Pranava, which contains all the Mantras in itself, and should also utter the three Vyahritis, as also the Savitri (212). Sadashiva is its Rishi, the verse is Trishtup, the presiding Deva is Savitri, and its object is the attainment of final liberation (213). The Gayatri Mantra is:
Ong, let us contemplate the wonderful Spirit of the Divine Creator. May He direct our understanding, Ong.
The Guru should then explain the meaning of the Gayatri (214-215). By the Tara, which contains the letters .i.e., A, U, and M.the Paresh is meant. He Who is the Protector, Destroyer, and Creator. He is the Deva Who is above Prakriti (106).
This Deva is the Spirit of the three worlds, containing in Himself the three qualities. By the three Vyahritis, therefore, the all-pervading Brahman is expressed (217). He Who is expressed by the Pranava and the Vyahritis is also known by the Savitri. Let us meditate upon the sublime, all-pervading eternal Truth, the great immanent and lustrous energy, adored by the self-controlled; Savita, effulgent and omnipresent One, Whose manifested form the world is, the Creator. May Bharga, Who witnesseth all, and is the Lord of all, direct and engage our mind, intelligence, and senses towards those acts, which lead to the attainment of Dharma, Artha, Kama, and Moksha (218-220).
O Devi! the excellent Guru, having thus instructed the disciple, and explained to him the Divine Wisdom, should direct him in the duties of a householder (221). "My Son! do thou now discard the garments of a Brahma-chari, and honour the Devas and Pitris according to the way revealed by Shambhu" (222). Thy body is sanctified by the instructions thou hast received in Divine Wisdom. Do thou, now that thou hast reached the stage of a householder, engage thyself in thy duties appropriate to that mode of life (223). Put on two sacred threads, two good pieces of cloth, jewels, shoes, umbrella, fragrant garland, and paste (224). The disciple should then take off his Kashaya cloth and his sacred thread of black-buck skin and his girdle, and give them and his staff, begging-bowl, and also what has been received by him in the shape of customary alms, to his Guru.
He should then put on two sacred threads and two fine cloths, and wear a garland of fragrant fiowers, and perfume himself, and thereafter sit in silence near the Guru, who should address him as follows (225-227):
"Conquer the senses, be truthful and devoted to the acquisition of Divine Knowledge and the study of the Vedas, and discharge the duties of a householder according to the rules prescribed in the Dharma Shastras" (228).
Having thus instructed the disciple, the Guru should make him offer three oblations into Fire in the name of Samudbhava with the
Hring, Earth, Firmament, and Heaven, Ong.
He should then himself perform Svishti-krit Homa, and then, O Gentle One! he should bring the investiture ceremony to a close by offering the complete oblation (229-230).
Beloved! all ceremonies, from the Jivaseka to Upana-yana ceremonies, are performed by the father alone. The ceremony relating to marriage may be performed either by the father or by the bridegroom himself (231). The pious man should on the day of marriage perform his ablutions and finish his daily duties, and should then worship the five Devas and the Divine Mothers, Gauri and others, and making the Vasu-dhara do Briddhi Shraddha (232). At night the betrothed bridegroom, preceded by vocal and musical instrumental music, should be brought to the chhaya-mandapa and seated on an excellent seat (233). The bridegroom should sit facing the East, and the giver of the bride should face the west, and the latter, after rinsing his mouth, should, with the assisting Brahmanas, say the words "Svasti" and "Riddhi" (234).
 
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