Before I came to Agathiyar, I had stayed away from worship for 13 years, having an issue with Erai over unanswered questions and doubts. Then Agathiyar through my nephew passes me Lord Vishnu's mantra. This episode itself was shrouded in mystery!
It was 4 pm on a Saturday afternoon on the 6th of October 2001 when my nephew, Thayalan came over to my house and told me he had to deliver something to me. He asked me over to my prayer room. I did not question him. He sat down, legs folded on the parquet floor of the first floor of my home. I sat opposite him. Again he said that he had been instructed to give me something that was long overdue, as he could not find time to come over. He asked me not to question the source. He shut his eyes, and went into a meditative state. His body shook and he spoke, asking me to repeat a Vishnu mantra thrice. He asked me to get a rosary and start chanting the mantra immediately. He also told me not to reveal to anyone what had just taken place then.
I started chanting the mantra that same evening without any reservation.
Wanting to know more about the mantra, I went through my collection of books. R Venu Gopalan in his, THE HIDDEN MYSTERIES OF KUNDALINI wrote that this mantra is recited for balancing the Vishnu Granti. He mentions this as the maha mantra of Lord Krishna and states the benefits derived from chanting it.
The nadis of the heart chakra is cleansed. It balances the heart chakra. Continuous practice of meditation on this mantra helps purify the thinking process. It also helps in dissolving all the past karmic deeds for a better future. The Vishnu Granti adds obstructions for the sadhaka keeping one under the wraps of attachment and bondage leading to the process of selfishness and supra ego.
In another book on Saint Dhruva, it is mentioned that this mantra was given to Dhruva by Saint Naradar who initiated Dhruva into the mysteries of yoga and meditation leading to samadhi.
Naradar taught Dhruva the practice of pranayama by inhaling, exhaling, and holding the breath. He taught Dhruva to overcome thought fluctuations with the help of breath control. Naradar also taught Dhruva to meditate on Vishnu in the sanctuary of his heart repeating the Lord’s name mentally and offer prayers and worship.
This mantra was mentioned in an extract from the English translation of the book KRIYA YOGA VIJNAN - THE SCIENCE OF KRIYA YOGA, the original by Saint Lahari Mahasaya.
Lahari Mahasaya has named this sadhana, omkar kriya. This is essentially a pranayama and the basis is the Vasudeva mantra. The sastras have propounded that the Vasudeva mantra is an omniscient mantra. When a sadhaka starts comprehending his awareness as one with the mantra then he becomes omniscient himself. Then his attainment shall be - I am this omniscient Vasudeva. In the Gita it is stated in the very last of all births, the man of wisdom worships me, realizing that all is Vasudeva. Rare indeed is the soul. Then do namaskar to thyself.
Wikipedia mentions the following,
‘Om Namo Bhagavate Vasudevaya’ is a mantra of Vishnu and Krishna both. It has two traditions - Tantric and Puranic. In Tantrik Tradition, the Rishi of the Mantra is Prajapati, in Puranic Tradition the Rishi is Narada. Both, however, say it is the Supreme Vishnu Mantra. Sharada Tilak Tantram (Sarada-Tilaka Tantram) for example, says "Dvadasharno mahamantrah pradhano Vaishnavagame" - the twelve lettered mantra is the chief among vaishnava mantras. Similarly, this is the ultimate mantra in Shrimad Bhagavatam, whose 12 Chapters are taken as extensions of the 12 Letters of this Mantra. This twelve syllable mantra is known as a Mukti (liberation) mantra and a spiritual formula for attaining freedom. This is the principal mantra of the Vedic scripture Srimad Bhagavatam. This can be chanted like Gayatri Mantra. This mantra can also be found in Vishnu Purana.
Yogi Professor Ramdas Prabhuji is of the same opinion with R Venu Gopalan, writes at https://lahirimahasayakriyayoga.org/om-namo-bhagavate-vasudevaya/
The purpose of the Second and Third Kriya is to break the heart granthi in order to get the fourth state, Turiya, or Samadhi. The heart knot is the Vishnu-Granthi. Therefore, the supreme Vishnu mantra (mahamantra) – om namo bhagavate vasudevaya – is used for this purpose. In the light of Kriya Yoga, the fourth state of Turiya, or Vasudeva, is a synonym for Kevala Kumbhaka.
The Vasudeva-mantra of 12 syllables – Om namo bhagavate vasudevaya – is known as a Mukti Mantra because it grants release from Samsara for the one who recites it with devotion and faith.From Awakening State at http://www.awakeningstate.com/spiritual-awakening/om-namo-bhagavate-vasudevaya/ we learn that,
This Sanskrit mantra can be practiced to attain freedom (moksha) from Samsara – the “Karmic Wheel” that keeps us bound to cycle after cycle of incarnations. This liberation mantra is a karmic eraser. Chanting this mantra with a sincere heart frees your mind and spirit from negative patterns in this life and helps us realize ourselves as a manifestation of transcendent divinity.
I continued to chant the mantra. I only came to know it was Agathiyar who wanted me to be initiated into the Vishnu mantra, a couple of years later. Agathiyar's desire was conveyed through Thayalan's Paramaguru who had come into a devotee.
A few days later Thayalan came over again to hand me a painting of Lord Dakshinamurthy and told me that I needed to worship Lord Dakshinamurthy in preparation to meet my guru. I was told my longing for a guru was to be realized. I did as told. Agathiyar came as Lord Dakshinamurthy ahead of my meeting my stula gurus.
A few days later Thayalan came over again to hand me a painting of Lord Dakshinamurthy and told me that I needed to worship Lord Dakshinamurthy in preparation to meet my guru. I was told my longing for a guru was to be realized. I did as told. Agathiyar came as Lord Dakshinamurthy ahead of my meeting my stula gurus.
Next Agathiyar drew me to read the Nadi, the following year. The Nadi too is shrouded in mystery!