It is believed that Sage Vikhanasa was created from the mind (Maanaseeka Udbhava) of Sriman NarayaNa, when many sages were reluctant to engage in the performance of AarAdhanam for Him in bhU lOkam because they were unsure of doing the right kind of ArAdhanam. They had no clue. Sriman NarAyaNa through viSEsha khananam (digging) created a new sage,named him VikhAnasa and empowered him to perform ArAdhanams for Him in His Vibhava and archAvatArams through upadEsams on Veda, VedAntams and initiation into Gayatri/Saavitri mantrams.
Sage Vikhanasar arrived at NaimisAraNyam, where the Lord is present as a Forest. He arrived there withhis Nine sishyAs, Atri, Brughu, Mareechi, Kasyapa, Vasishta, Pulaha, Pulashtya Krathu and Angiras in the time of Swayambhuva (The 1st one)Manvantaram, Sukla Paksham, SrAvana Pournami, Monday, Simhalagnam with star of Sravanam according to Sage MarIchI's Ananda SamhitA.
Among them four sishyas Atri, Bhrigu, Marichi and KAsyapa has written the major portion of Sri Vaikhanasa Bhagavachhastram based on the teachings of Vikhanasa Maharshi. Sage Vikhanasa blessed the world with one and half crores of PramAnams in his Aagamam. The four sishyAs condensed these vast numbers of PramAnams to a smaller subset of four Lakhs of grantams to make it simpler for the human beings to follow for the worship of the Lord through VaikhAnasa Aagamam (sUtram VikhanasA prOktam saardhakODi pramANakam, chaturlaksha pramANEna samkshipya prOchyatE adhunA).
The Vaikhanasas as a community are temple priests. They regard themselves as ordained by birth to be temple priests and they are enjoined not to follow other avocation in life. Vishnu himself is said to have declared that those who follow the Vaikhanasa Sutra are dearer to him.
In a verse in Varaha Purana Lord Vishnu says that the Aswatha Tree, the Red Cows, the tulasi plant and the sage Vikhanasa (the ancestor of the community) are the four things that are dear to him, and that among the four, Sage Vikhanas is the dearest.
Ananda Samhitha (Marichi) states that the Sage Vikhanasa who prepared the Vaikhanasa Sutra according to a branch of Yajurveda was Brahma himself.
AdikAlEtu bhagavAn brahmA tu viKhanA muni: |
Yaju: shAkhAnusArE chakrE sUtra mahattaram ||
Kriyadhikara (Bhrigu) identifies Vikhanasa with Vishnu or with the first sage who appeared as an aspect of Vishnu (viz, Brahma), and says that the Sutra was taught by this sage.
viKhanAvai vishNu: tajjA vaiKhAnsA smritA: |
vishNuvamsajaSva viKhAnA munInAm prathamO muni: |
tEnOpadishta yatsUtram tatsUtrEshUttamam smritam |
Brahma, the creator, who was the offspring of Vishnu, was called the firstsage, and was called Vikhanasa, because he dug into his own mind (manasAh KhananAt) for creating the scriptural lore.
viKhanA iti prOkthO manasa: KhananAt suta: |
brahmaNA: suvisEshENa munInA prathamO muni: ||
Digging up into (Khanana) appears to be in the background of the expression Vikhanas. Several shades of meaning have been projected.
Ananda Samhita speaks of Vishnu 'digging up' the essential import of the Upanishads before he gave the scriptural lore of the Vaikhanasas.
vEdAntatattvamImAmsAKhananam krutavan hari: |
nAmnA viKhanasam chakrE tatpadAnvarthayOgata: ||
Digging into the meaning of Veda or intense inquiry into the thrust of the Vedic corpus was said to have been accomplished by the first sage, who was therefore called as Vikhanasa.
KhananAdviKhanA muni: |
Khananam tatvamImAmsEtyAhu |
nigamArthAnAm KhananAditi na: Srutam |
Digging out the hidden meaning of Vedas and revealing them to the human beings, according to Ananda Samhita, were the tasks that Vishnu accomplished and therefore he became known as Vikhanasa, and his offspring who was the progenitor of all was known as Vaikhanasa.
antarhitAnAm KhananAdvEdAnAm tu visEshata: |
sa vibhu: prOchyatE sarvairviKhanA brahmavAdibhi: ||
vaiKhAnasaSva bhagavAn prOchyatE sa pithAmaha: ||
When the word Vikhanasa, in the background expression, is interpreted as referring to Brahma, the creator, a distinction is made in Nrisimha Purana, between the older Brahma (Agraja), who was born out of Vishnu's mind with only one head and who became the author of the Sutras, and the younger
Brahma (Anuja), who was born out of Vishnu's navel, with four faces, for producing the worlds and denizens in them. Vikhanasa, who was the 'older' Brahma, became the 'younger' Brahma after six incarnations (incarnation meaning 'Manvantharam' and now it's the 7th Manvantharam). The sages Bhrigu, Atri, Marichi and Kasyapa are said to have received the cult of Vishnu from the first Vikhanasa (viz., the older Brahma in Svayambhuva Manvantharam).
The approach of the Vaikhanasa worship is described as peaceful (soumya).
Thus, the expression vikhanas (with its derived form Vaikhanasa) has many shades of meaning: the great god Vishnu himself, the creator Brahma who appeared from his navel-lotus, the great sage who was mind born and who was instructed by Vishnu himself in the matter of worship, the sage who was the progenitor of the lines of the Vaikhanasa devotees, the divine author of the sutras known after him, and the hermit who was in the third stage of life. It is probable that the Vaikhanasa community was so called because of the involvement in all of these aspects.
More importantly, Vaikhanasas are distinguished by their uncompromising adoption of the Vaikhanasa-Sutra, which is devoted in all its parts to Vishnu and which was initially communicated by Vishnu himself to the sage Vikhanasa.
AdikAlEtu bhagavAn brahmA tu viKhanA muni: |
Yaju: SAKhAnusArENa chakrE sUtram mahattaram |
tatsUtravidhyanushtAnAt smritA vaiKhAnasAstu tE |
yatsUtrAdyantamadhyEshu bhagavAn vishNuravyaya: || (from Atri's Pura-Tantram)
The sage Vikhanas (or the primordial Vikhanasa) is adored by the community in its daily prayer as one who is sustained by Vishnu (achyutagam-srayAya), who is engaged in severe austerities (tapOgra-nishta), and who is the knower of the highest principle (brahma-darsin). He is described as an expert in the worship of Vishnu (Vishnu-pUjA-visArada), as four armed and seated upon a tortoise seat holding in his hands, the sacred water pot, rosary and ascetic's staff. He is worshipped as present on the right side of Vishnu's main idol 'Dhruva-bera'.
Vikhanasa is also described as having Vishnu as his father and Lakshmi as his mother, and sages like Bhrigu as his disciples:
nArAyaNa: pithA yasya mAtA chApi hari priyA |
bhrugvAdi munaya: SishyAstasmai viKhaNasE nama: ||
Atri Maharshi gives the story of how the Brahma obtained from Vishnu the Vaikhanasa sutra.
At the beginning of creation, Vishnu taught the creator Brahma, the method of worship according to the Vedic corpus. This teaching was a thousand crore of verses in extent ('sahasra-kOtibhis slokaih sAnKhyatAm bahu vistAram'). But this elaborate worship manual disappeared in course of time. Then Brahma went to Naimisa forest as an ascetic with matted hair on the head, and began to perform severe penance. He meditated for long years on Vishnu and by the power of penance perceived the Agama (scripture explaining the worship procedure) elaborately as it was once taught by Vishnu (apasyAd Vishnuktam Agamam vistArat tada). He was now known as Vikhanas or great sage. He abridged the elaborate teachings, retaining the most essential aspects (samkshipya sAram AdAya) and taught this version, which was like a well-carved gem (sanolliKhita-ratnAvat), to his sons, Marichi and others, who were hermits. This version was one and half crore of verses in extent.
dhAtA viKhanasO nAma marIchyAdistutAnmunIn |
abOdhayadidam ShAstram sArthakOti pramANata: ||
The sages who received this abridged teaching were four in number; and asthey were the offsprings of Vikhanas, they came to be recognized as Vaikhanasas: Marichi, Bhrigu, Atri and Kasyapa. They recast and further condensed the teaching in four lakhs of verses ('chAturlaksheshu granthEsu samkshipya samhitah'). And they were responsible for the formation of the Vaikhansa community.According to Marichi, the arrival of Vikhanasa Maharshi in the Naimisa forest was on a Monday, when there was full moon and lagna was simha, during the bright half of the Sravana month, in the era which began with Swayambhuva Manu.
sravanE srAvanE sukla pourNimA sOmavAsarE |
simha lagnEcha samyuktE bhajE naimisamAgatam ||
'Kriyadhikara' by Sage Bhrigu provides a more elaborative description on how the Vaikhanasa mode of worship was instituted. When Vishnu at the beginning of the Kalpa was absorbed in meditational slumber (yoga-nidra) upon the milky ocean, Brahma appeared, in the lotus, which sprang forth from Vishnu's navel.
Brahma, four faced, contemplated upon Vishnu as soon as he appeared, whereupon Vishnu directed him to create all the worlds and all the creatures in them, and gave him the Veda mantrAs to help him in the creation. Brahma created all things, all beings and all the gods, and worshipped Vishnu with the Vedic hymns. However, he became proud of his ability to create and became arrogant. Vishnu, in order to correct him, brought forth, two demons, Madhu and Kaitabha, who assaulted Brahma and snatched from him the VedAs, which they hid in the depths of the ocean. Brahma with his power (Vedic Corpus) gone, became grief-stricken, and wondered how he should worship Vishnu now that the Vedic hymns were no longer available to him. Vishnu advised him to worship him for five days with the repetition of the twelve-lettered and eight-lettered mantras -dvAdasAksharam and ashtAksharam. This became what is known as the Pancharathra method of worship. Then Vishnu decided to fight, and diving deep into the ocean killed the demons Madhu and Kaitabha. He brought the Vedas up and gave them to Brahma, who was overjoyed and began worshipping Vishnu again with the Vedic hymns (viz., in the Vaikhanasa way).
Arrogance entered Brahma's mind a second time, and Vishnu, in order to correct him, created the demon Somaka, who attacked Brahma and took away the Vedas from him. Distraught, Brahma again approached Vishnu and asked him how he should be worshipped, now the Vedas having again gone out of his possession.
Vishnu advised him to worship without any mantras and in accordance with the Tantrik procedure. This is known as the Agneya mode of worship. Vishnu assumed the form of a great fish (Matsya), and killed the demon Somakasura with his great power. He brought back the Vedas and gave them to Brahma. Brahma was happy and he began again worshipping Vishnu with the Vedic hymns. Thus the Vaikhanasa mode of worship came to stay.
The Vaikhanasas, tracing as they do their descent from Vishnu himself, regard themselves as Vishnu-devotees from their very birth (garbha-vaishnava- janmanam), not needing any other initiatory rites or diksha during their lives to make them Vishnu-devotees. The sacramental rites that are prevalent in a Vaikhanasa household include a symbolic ceremony, unique to this community, known as Vishnu-Bali (or garbha-chakra-samskaram). Prescribed to be performed during the bright half of the eighth month of pregnancy (garbhadhadyashtame masyeva sukla pakshe) in order to protect the individual within the womb of the prospective mother (asyah garbha-samrakshanartham).
Vishnu-bali is a sacrament which follows 'seemantha' (the ritual before child birth). The significance of this ritual is that an offering (Bali) is made to Vishnu (Vishnu-devatako balih upahriyate asmin); and even inside the mother's womb, the foetus acquires the status of a Vishnu-devotee (garbhastha sisoh garbhavaishnavatva siddhyartham). The ceremony involves a fire-ritual and offering to the pregnant lady, the sacrificial sweet rice-pudding (pAyasa) in which the emblems of Vishnu (Chakra and Sankha) has previously been dipped and a part offered to the fire. While the woman is drinking the remainder of the rice-pudding, the following mantra is recited.
tvatsutO bhAgyavAn dhanyO garbhavaishnava sangnita: |
aprAkrutO mahAtmAsau garbhachakrENa lAnchita: || (Sri Vaikhanasa Kalpa Sutram)
The belief is that Vishnu himself will brand on the arms of the individual to be born the marks of the conch and discus, which He carries in His own hands. Thus the person is a Vaishnava, even when he is born, and he is regarded as the offspring of Vishnu viz., Vaikhanasa.
The practical import of this ceremony is that the child born as a Vaikhansa is already sanctified and initiated by Vishnu himself and does not need any other sacrament or initiatory rite to make him a Vishnu-devotee or a qualified priest. He acquires the right to be a priest by his very birth.
This is in contrast to the priests of other communities (as for eg. The Pancharathrins), for whom during the boyhood a formal ceremony of branding the arms with heated metallic images of Vishnu's conch and discus (tapta-mudrankana or samAsrayanam) is conducted.
The Vaikhanasa know their scripture only as 'Bhavagachhastra'; their implicit acceptance of Vedic authority was well known even to the ancient smriti-karas like Baudhayana, idol worship was not for them a substitute for the Vedic ritual, but was itself in their view, a Vedic ritual. Hence the sutra prescription,
tasmAdagnau nityahOmAntE vishnurnityArchA gruhE dEvAyatanE bhaktyA
bhagavantam nArAyanamarchayEt ||
There is an intriguing verse in Vishnu-Purana, which has been cited and explained by Srinivasa-Deekshita in his Tatparya-Chintamani (Uttama brahma vidya saram),
yajvabhiryagnapurushO vAsudEvaSva sAtvatau: |
vEdAntavEdibhirvishnu: prOchyatE yO natOsmi tam ||
Godhead here is described as what the sacrificers (viz. the Vedic ritualists) worship as Yajna-Purusha (viz. the personification of sacrifice), the Sattvatas (viz, the Pancharathras) regards as Vasudeva, and the knowers of the final import of the Veda (viz. the Vaikhanasas) as Vishnu. Srinivasa-Deekshita (or Srinivasa-Makhin) distinguishes between the 'sacrificers' (viz. the knowers of the Veda,'vEda vidbhih Vaikhanasaih' also a group among the Vaikhanasas, devoted to the idol less rituals prescribed in the Veda, 'amUrtArchanam') and the knowers of Vedanta (viz. worshippers of idol representations of Vishnu, 'samUrta-bhagavadyajanam'), who are also Vaikhanasas.
These details are available at link.