After the passing away of Govindapada, Shankara along with a few other Sanyasins proceeded towards Varanasi even as his Guru had counseled him. He passed through the Vindhya forests, and visited Prayaga, the great confluence of rivers and a noted pilgrim center. From there he walked on to Kashi, the city of knowledge and salvation. He stayed in the Manikarnika Ghat in Varanasi in a secluded and quiet spot. Suffused as his mind was with the consciousness of Brahman, he found Varanasi peculiarly suited to his temperament. Bathing in the waters of the holy Ganga and having the Darshan of Lord Vishwanatha and Mother Annapurana Visalakshi every day, he was immersed most of the time in meditation, his cultured mind freed from all worldly fretters, easily finding its habitat in the contemplation of the ` Satyam Jnanam Anantam Brahma `- the Absolute that is Truth, Wisdom and Infinity. It was not however possible for him to stay for long in solitude. He got easily `discovered'. He was self-luminous and earnest seekers and scholars flocked to him in increasing numbers. He was too kind- hearted to turn them away even for the self-absorption that he so much relished. He gladly began teaching them and telling them of the Ultimate Truth. Within a very short time, his vast learning, unusual gifts of exposition, astounding intellectual keenness and charming personality became the talk of the town. Scholars and monks belonging to diverse philosophical sects and schools and owing allegiance to various systems of thought approached Shankara and had their doubts cleared on the Ultimate Truth. Shankara's life task of re- establishing the pure Vedic faith in the whole of India thus had its auspicious beginnings in Varanasi.
Shankara re-established in the undivided Bharat, the Sanatana Vaidika Dharma by freeing the entire country from the baneful influence of distorted and decayed Buddhism and Jainism. It was because of his life that the Vedas and Vedic faith were protected and preserved. He did not build the monastic order only ( the ten monastic orders Shankara established are Tirtha, Ashrama, Vana, Aranya, Giri, Parvata, Sagara, Saraswati, Bharati and Puri). He entrusted the great responsibility of sustaining and protecting the Sanatana Dharma to the Sanyasins, especially to the Abbots of the Maths he established. As a result of this within a short time the Vedic religion revived in the whole of India. He was the architect of the glorious renaissance. It was because of the vitality infused into the Vedic Dharma that in later years despite heavy onrush and oppression of the outsiders and people of differing creeds that India could stand firm and maintain her distinct cultural identity. Hence even today the Sanatana Vedic Dharma is not only alive but her influence in full glory has spread throughout the globe.
Even from pre-historic times, Varanasi has been one of the chief centers of Sanatana Vedic Dharma. It has verily been the abode of the serene God, Shiva Vishwanatha ever lost in the contemplation of his own Gory. Countless generations of spiritual aspirants of diverse schools and renowned scholars of varied interests have realized the fulfillment of their mission in the holy city of Kashi. At the time of Shankara's arrival in Varanasi, there lived in it aspirants belonging to many different sects- Shaiva, Pashupata, Sankhya, Patanjala, Soura, Shakta, Ganapatya, Jaina and Bauddha orders of seekers and scholars, all intent on achieving the Supreme God in ways suited to them. Many of them were drawn to Shankara hearing the news of his arrival and about his genius and soon Shankara's lodgings became a place of sacred pilgrimage. Many, to establish the superiority of their view points, wound enter into debate with Shankara. He lent them patient hearing and with comfortable ease disarmed them all by irrefutable reasonings.
In the presence of the genius and personality of the boy-Sanyasin, the parties aspiring for victory were humbled and the opposing contestants felt blessed realizing the Truth. The earnest inquirers would get all their doubts resolved and desire new light in their spiritual lives. The Sadhaka would feel gratified and receive great inspiration in strengthening his spiritual living. Shankara's stay at Varanasi led the spiritual thought-current of the place to flow in full-flood state.
A Brahmin youth named Sanandana of the Chola country in South India happened to arrive at Varanasi when Shankara was staying there. He had been for a long time journeying through many places in search of a realized Guru who would put him on the sure path to Ultimate Knowledge. It did not take him long to come to hear of the eminence of Shankara. He heard of Shankara's supernatural power and uncommon genius and developed a high regard for Shankara and made bold to go to him one day with a request to him to be his Guru. Shankara was delighted to meet Sanandana. He surveyed the supplicating youth, saw his worth, and after putting a few queries in order to know something of his past, gave him permission to stay with him. An intimacy of few days was sufficient to convince Sanandana his Guru of the godly life of Shankara. He made a gift of himself to his Guru. He ardently believed that if he could get the grace of Shankara, he could attain the summum bonum of life- the self-realization. So one day he begged of Shankara to initiate him into Sanyasa. Shankara was in a gracious mood and on an auspicious day, initiated Sanandana into Sanyasa. Thus Sanandana became the first Sanyasi disciple fo Shankara.
Sanandana was in every way worthy of Shankara. Even as a boy he had developed a religious turn of mind, felt an intense dispassion for things of the world and had proceeded to a hill called Ahobala in the south to realize God-vision. He had heard that Nrisimhadeva, the man- lion incarnation of Narayana, who is easily pleased with men and fulfils ardent desires of those who pray for his vision was ever available to sincere seekers in that place. Living on a fruit-diet in the forests on the hill, Sanandana had engaged himself in the worship of Nrisimha. His yearning for God-Vision grew intense day by day. One day a youthful hunter came to him and asked him, " why is it that you live alone in this desolate uninhabited forest ? " Sanandana did not like to give out his real intention, nor did he like to be guilty of an untruth. So he gave the hunter a clever reply, " I am looking for a creature with a lion's face and a human body. Can you help me find it? " The hunter retreated without a word and then returned after a while with an image of Nrisimha wrapped in green leaves and bound by tender creepers. Sanandana prostrated before this image and burst into a prayer. The hunter disappeared from view and the living form of Nrisimhadeva stood before Sanandana, asking him, " Dear child, ask for a boon." Sanandana asked for the boon of Abhaya, fearlessness and " It is also my prayer that you appear before me to help me out of any difficulty I may find myself in, whenever I remember you and desire your intervention. " " Be it so, " said Nrisimha as he withdrew out of sight.
Blessed Sanandana regarded it as a stroke of singular good fortune that a Guru of Shankara's eminence had condescended to adopt him as his disciple. He was highly devoted to his Guru. Guruseva was indeed his penance. Like his very shadow, he constantly stayed by the side of Shankara. His greatest Sadhana lay in serving his Guru. Endowed with a superior intelligence and a deep knowledge of the scriptures, he was able to win the complete confidence of his master whose favorite he soon became. He was literally to Shankara what Hanuman was to Sri Rama. On may an occasion he saved the life of Shankara from coming to an untimely end, never hesitating to put his own life into danger.
Shankara's masterly proficiency in the Vedic scriptures and his study of and training in Yoga under the expert direction of Govindapada had helped him to scale the heights of the realization of the ultimate reality. He was established totally in self-awareness. To him, in his lofty perch, Brahman alone was Truth, the universe but an illusion, and the seemingly bound soul, Jiva, was none but the Brahman. The grand non-dual knowledge of the individual soul and the Total Brahman, the Supreme soul, is experienced in the deepest state of super-conscious Samadhi or utter indrawnness. However on the worldly plane where the normal senses function in our practical day to day work and behavior, it is possible in a partial way to maintain undistorted this perception of Brahman in all, only as a result of prolonged and steady practice. Over and above everything else, the Grace of God is needed. The attainment of this state of experience is extremely different and a very rare privilege for ordinary mortals. It is but natural for great men and Avadhootas like Sri Dattatreya, Sri Shankara, Sadashiva Brahmendra etc.