Brahma had a son by name Ribhu. Ribhu, by his very nature, possessed a sound knowledge of Brahman. Nidagha, the son of Maharshi Pulastya, was a disciple of Ribhu. Pleased with the good qualities of Nidagha, Ribhu instructed his disciple fully in the knowledge of the Brahman. Ribhu found out that his disciple, though proficient in all the scriptures, was not steady in the knowledge of the Brahman, because he was not able to cognise the one Reality underlying the various objects of the Universe.
Nidagha went and settled himself in Viranagar on the banks of the river Devika and began to lead an ideal life bearing in mind at all times the duties of a true householder. After the lapse of a long time Ribhu went to Viranagar with the object of seeing his disciple Nidagha. Nidagha was waiting at the gate in expectation of a guest after duly performing his daily sacrificial rites. Nidagha welcomed Ribhu warmly and took him inside the house. Nidagha duly worshipped the noble guest and humbly requested him to take his dinner.
Ribhu said, O Brahmin! Please tell me what kind of food you will serve me today. I do not relish unholy foods. Nidagha said, I have got in my house wheat-flour, maize, fruits, roots and loaves of bread. Of these whichever you like I shall be pleased to serve you with.
Ribhu said, I do not want all these useless food-stuffs. Give me good sweets, rice boiled in milk, curds, molasses and other delicious articles.
Then Nidagha said to his wife, O mistress! Soon make ready a very palatable and savoury meal for our guest today with the best of articles available in the house. According to the wishes of her husband, Nidagha's wife prepared the dinner and he fed Ribhu sumptuously. When Ribhu had just finished his dinner Nidagha humbly requested him thus: O my venerable guest! Was the food tasty? Are you fully satisfied? Where do you live? Where are you proceeding now and wherefrom are you coming?
Ribhu replied, He who is hungry becomes satisfied when he takes a hearty meal. I was never hungry at all and why do you put me this question? When by the constant working of the Jatharagni (digestive fire) the digestive organs get tired, man feels hungry and when the water in the system gets exhausted he feels thirsty. Hunger and thirst are the Dharmas of the body and not mine. Since there is no hunger at all for me, I am always satisfied. Pleasure and satisfaction are the functions of the mind. I am not the mind too. Enquire then about these things whose Dharma is satisfaction, pleasure etc.
Now hearken to me about the other questions 'Where do you live? Where do you go? And wherefrom are you coming?' Atman or the Self is all-pervading like the ether and therefore these questions do not at all apply to It. The questions themselves are without basis. I do not go anywhere. I do not come from any place and I do not remain in any one place. These differences of 'I', 'he' and 'you' are in respect of the different bodies and not in reality. The truth is that you are not you. I am not myself nor is he another different from the other two.
A sweet thing is not always sweet. When I requested of you sweet rice etc., my intention was simply to know what you would say. For the really hungry man everything is palatable. The same food which is palatable once begins to give the reverse impression the next moment. When man has taken food to his heart's content even the most delicious food causes retching. Thus the tasty food becomes non-tasty and vice versa. Further, is there any such food which is uniformly tasty in the beginning, middle and end? This physical body made of earth is kept up by food which is also earth particles in reality. Just as the wall built out of clay is kept strong by coating it with clay now and then, this body also remains healthy and strong by the atoms of food that we take. Barley, wheat, green dhall, oil, milk, curds, sugar, fruits, etc., are all mere atoms of earth only. Then which of these are we to call tasty and which non-tasty? Knowing thus you should educate your differentiating mind and try to see the one underlying thing in all and you should become serene. Serenity is the most important qualification for the attainment of Moksha.
Hearing these words of wisdom Nidagha prostrated before Ribhu and humbly said, O Revered sir! Be gracious unto me. Please reveal thy identity. I think you have come here to bless me with the true knowledge. by hearing your soul-elevating speech I am free from all delusions.
Ribhu replied, O Brahmin! I am your preceptor Ribhu. I came here to give you the knowledge of the Self by which you will be able to distinguish the real from the unreal. I take leave of you now. That which is true and which is fit to be known, I have already told you. Ever meditating on these truths may you find the whole world indwelt by the one Vasudeva! There is not even a grain of difference or duality in it.
Nidagha paid his due respects, worshipped his Guru and lived happily in the true spirit of the teachings of his Guru.
After a long number of years had rolled on, Maharshi Ribhu, in order to instruct Nidagha in the knowledge of Self, again went to Viranagar City. When he reached the city he saw that the king of the country had entered the city with a big crowd of followers. He found big crowds of men in every nook and corner of the town busily engaged in the reception of the king. Ribhu noticed Nidagha standing in a secluded place far away from the crowds with Kusa and Samidha in his hands. Nidagha was much afflicted by hunger and thirst but he could not proceed further towards his house due to the huge crowd of men obstructing his way.
Ribhu went near Nidagha and questioned him thus: Dear Brahmin! Why are you standing here alone in quite a solitary corner? Nidagha replied, Today the king of this country has come here and there is much crowd waiting upon him and I cannot push my way through the crowd. Hence I am forced to wait here.
Ribhu said, You seem to know all about this place. Please tell me who is the king and who are the others. Nidagha said, He who is seated on the huge elephant which resembles a big mountain, is the king, and the others are his courtiers who have accompanied him.
Ribhu said, Revered sir, you have described both the elephant and the king jointly and of the two I am at a loss to know who is the king and which is the elephant. You did not definitely point out or give me the description of both distinctly. That I would like to know from you. Nidagha said, Of these that which is below is the elephant and one who sits over it is the king. They have the connection of the carrier and the carried. I do not think that there is anyone who cannot understand even this.
Ribhu said, Yes, I understood that. But please tell me what the words 'below' and 'above' mean. How am I to understand which is up and which is down?
Nidagha at once got upon the shoulders of Ribhu and exclaimed, Look here, O Brahmin, hearken to me. I shall reply your query. Now I stand 'up' like the king and you stand 'down' like the elephant. This illustration I have given you practically to make you thoroughly understand what is 'up' and what is 'down'.
Ribhu said, What is 'up' and 'down'? They are relative terms. 'Up' becomes 'down' and 'down' becomes 'up' from different positions or angles of vision. You told me now that you were standing up like the king and that I was standing down like the elephant. Please tell me 'who are you? who am I?' I am very eager to know the truth of this. Hearing these words Nidagha prostrated at Ribhu's feet and said, O Lord! You are none other than Rishi Ribhu, my beloved preceptor. No one else can speak like this. You are very intelligent. You who stand in front of me are no other than Maharshi Ribhu. Pray bless me.
Then Ribhu said, O Nidagha! Once you served me with great faith and devotion and welcomed me in your house. You bestowed on me great honour. So bound by the cords of your affection I, known as Ribhu, have come to you once again to instruct you in the knowledge of the Self. O thou of high intellect! Always behold the one reality of the Self in all objects of the world. May you see oneness everywhere and not duality. Saying thus Ribhu departed.
Nidagha contemplated over the nectar-like words of his Guru and attained union with the Para Brahman. He was never again deluded by the charms of Maya. The world of duality entirely vanished and he saw the one homogeneous essence in every object from a blade of grass to the state of the Brahma.