After the war of Kurukṣetra (Kurukshetra) and the coronation of Yudhiṣṭhira (Yudhishthira), Kṛṣṇa (Krishna) and the Pāṇḍava (Pandava) went to visit Bhīṣma (Bhishma), lying on his śaraśayya (sarasayya; bed of arrroes). Throughout Śāntiparva (Santiparva) and Anuśāsanaparva (Anusasanaparva) of the Mahābhārata (Mahbharata), there is an elaborate description of the dying Bhīṣma’s (Bhishma’s) advises to the Pāṇḍava (Pandava). Answering the queries of his grandson Yudhiṣṭhira (Yudhishthira), Bhīṣma (Bhishma) pours out his knowledge and experience regarding political, philosophical and spiritual experiences of his long life, as if he sought to transmit his wisdom to the surviving generation of the Kuru dynasty. Ṛṣabhagītā (Rishabhagita) was part of those advisory discourses of Bhīṣma (Bhishma).
One adhyāya (adhyaya or chapter) of the upaparva called Rājadharmānuśasana (Rajadharmaanusasana) in Śantiparva (Santiparva) begins with the question of Yudhiṣṭhira (Yudhishthira) — O grandsire! From where does āśā (asa or hope) emerge? And what is meant by āśā (asa, hope) —
Kathamāśā samutpannā kā ca sā tadvadasva me.
Yudhiṣṭhira (Yudhishthira) was at that time suffering from repentance, considering himself responsible for the mass destruction at the war of Kurukṣetra (Kurukshetra). The question he asked about hope, was also charged with this guilt-feeling. When Yudhiṣṭhita (Yudhishthira)said –when the Ajñātavāsa (Ajnatavasa) was over, I hoped that Duryodhana would legitimately return me the kingdom I lost. But when that hope was thwarted, some ill notion seemed to overpower me — resulting in this terrible war —
Pitāmahāśā mahatī mamāsiddhi suyodhane.
Prāpte yuddhe tu tad yuktam tatkartāyamiti prabho.
So’ham hataśo durbuddhiḥ kṛtastena durātmanā.
Bhīṣma (Bhishma) understood how deeply Yudhiṣthira (Yudhishthira) was suffering from trauma of the war. So, while explaining what hope is, he also tried to console his grandson. Talking of hope and how painful it is, Bhīṣma (Bhishma) alluded to the legend of king Sumitra and sage Ṛṣabha (Rishabha). The advises of Maharṣi Ṛṣabha (Maharshi Rishabha) about āśā  (asa or hope) forms a discourse called Ṛṣabhagītā (Rishabhagita). Āśā (Asa or hope) is a parā of the human mind. It is not easy to define it or philosophically analyse it. When Bhīṣma (Bhishma) referred to the story of Ṛṣabha (Rishabha). In this story, while talking about the birth of Āśā (Asa or hope) and the state of mental hopelessness, Maharśi Ṛṣabha ( Maharshi Rishabha) narrated an ancient tale. Ṛṣabhagīta (Rishabhagita) was consisted of the combination of Bhīṣma’s (Bhishma’s) narrative and the ancient story within it. This combined narrative did not only tell about Āśā (Asa or hope) and being āśāhata (asahata or hopeless), it also indicated the path get freedom from the earthly desire, illusions and the chain of hope.

Kuru grandfather Bhīṣma (Bhishma) continued to narrate- Sumitra was the king of the Haihaya dynasty. Once he went to hunting. There he saw a deer. He threw an arrow aiming at the deer. But the wounded deer flew away. While following the deer, the king moved into the dense forest. But he could not find the deer. There was a hermitage of meditative ṛṣis (rishis or saints) in the forest. Being tired and exhausted, the king entered into the hermitage. The meditative ṛṣis (rishis or saints) took care of the king who was then hungry and exhausted. They made good arrangements for his food and rest. When the tired king was a bit relieved after the good care of the ṛṣis (rishis or saints), they asked the king why he came into this dense forest. The king told the ṛṣis (rishis or saints) about his hunting expedition. He did not conceal his sad and hopeless mental condition as he could not find the deer. The words of king Sumitra represented how, even a denial of small desires could result in great sadness. He told-” I am so sad after losing the hope of getting the deer. I would not be so depressed even if I have to give up my kingdom or to leave my capital.I am so overwhelmed by the hope and the subsequent hopelessness that I feel that this pain is greater than the Himālaya (Himalaya) mountain, the seas and even greater than the skies. I cannot get over it-
Na rājalakṣaṇatyāgo na purasya tapodhanāḥ.
Dukhaḥṃ karoti tattībraṃ yadvāśā vihatā mama.
Himavān vā mahāśailaḥ samudro vā mahodadhiḥ.
Mahattvānnanvapadyetāṃ nabhaso vantaraṃ tathā.

After expressing his disappointment, the king ultimately asked the wise sages- ” You are all wise men. Kindly tell me which is greater- the human hope or the vast sky? I cannot overcome my hope in any way. Please show me the way-
Bhavantaḥ sumahābhāgāstasmāt pṛcchami saṁśayaṃ.
Āśāvān puruṣo jaḥ syādantarikṣamathāpi vā.”

Maharṣi Ṛṣabha (Maharshi Rishabha) was there with the other sages in that hermitage. He came forward to clear the doubts of king Sumitra. Maharṣi Ṛṣabha (Maharshi Rishabha) told the king the tale of Tanumuni, an inhabitant of the Vadarikāśrama (Vadarikasrama). Ṛṣabha (Rishabha) said, “Once I traveled to many sights of pilgrimage. Then I reached the hermitage of Nara-Nārāyaṇa (Nara- Narayana) at Vadarikāśrama (Vadarikasrama). I had a bath and offered my tarpaṇa (tarpana or prayers to the forefathers) at that pious place of pilgrimage. Then I saw that a sage called Tanu was coming towards this āśrama (asrama or a place where the sages live). He wore Koupīna (Koupina or a kind of loincloth) and the skin of the barking dear. He was quite tall, but very thin in body”. Maharṣi Ṛṣabha (Maharshi Rishabha) gave a detailed physical description of Tanu Muni. In height, Tanu Muni was almost eight times taller than ordinary men. But he was so thin that the breadth of his body could be compared with that of a little finger of a man-
Anaiyrnarairmahāvāho vapuṣāṣtaguṇānvitaṃ.
Kṛśatā cāpi rājarṣe na dṛṣtā tādṛśī kvacit.
Śarīramapi rājendra tasya kaniṣthikāsamaṃ.

Maharṣi Ṛṣabha (Maharshi Rishabha) touched the feet of this weird looking sage to pay him respect. Tanu Muni asked Maharṣi Ṛṣabha (Maharshi Rishabha) to sit near him and inquired about his identity. Then he began to advice the sages present there. At that time, a king called Vīradyumna (Viradyumna) arrived there. His only son Bhūridyumna (Bhuridyumna) had been missing for some days. In search of his son, the despondent king with his wife had arrived in Vadrikāśrama (Vadrikasrama). He hoped that he could find his son there. While mourning for his missing son, king Vīradyumna (Viradyumna) came before Tanu Muni. He had the same question in his mind- ” What is hope? How can one overcome hope? What is greater than hope in this earth?”
Durlabhaṃ kiṃ nu devarṣe āśāyāścaiva kiṃ mahat.

Tanu Muni became depressed looking at the king suffering from pain for his missing son. He quitely responded to the questions of the king- ” Mahārāja (Maharaja or the great king), once a sage asked for a gold pitcher and deer skin from your son. He hoped that your son would fulfill his wish. But his wish was not fulfilled. Rather he was ignored and insulted. The hopeless sage suffered ignominy”. After saying this, Tanu Muni then became silent and bowed down his head. Tanu Muni’s reaction indirectly indicated that the sage who was insulted and disappointed by the son of Vīradyumna (Viradyumna) was Tanu Muni himself. But Tanu Muni tried to speak impersonally-“Mahārāja (Maharaja), After getting insulted and rejected, the sage took a pledge that he would not take any gift from any king in his lifetime. Then he devoted himself to strict meditation-
Sa hi tena purā vipro rājñā nātyaārthamānitaḥ.
Āśākṛtaśca rājendra tapo dīrghaṃ samāśritaḥ.
Pratigrahamahaṃ rājñāṃ na kariṣye kathañcana.
Anyeṣāñcaiva varṇānamiti kṛtvā dhiyaṃ tadā.

Then Maharṣi Ṛṣabha (Maharshi Rishabha) continued his narrative- “While advising on the idea of hope, Tanu Muni then clearly referred to his own issue. He wanted king Vīradyumna (Viradyumna) to remember his past insults-
Tataḥ saṁsmṛtya tat sarvaṃ smārayiṣyannivavravīt.
Rājānaṃ bhagavān viprastataḥ kṛśatanustadā.

For the first time, Tanu Muni told his own tale. He said- “Mahārāja (Maharaja), the thing of hope cannot be found easily. So no one was weaker than the person who was driven by hope and who suffered after being disappointed”. But Tanu Muni did not talk about physical weakness. Rather he referred to mental weakness, being mentally powerless and depressed.
Then king Vīradyumna (Viradyumna) asked him- ” Maharṣi (Maharshi or the great sage), is there someone in this earth who was thinner than you?” In reply, Tanu Muni explained the significance of his physical thinness- ” After being disappointed, I realized that hope is the root of human misery in this earth. Then I tried to restrict my hope which is inherently connected with human mind. After strict meditation, now I am successful to sacrifice hope. When the father has lost his son, he has a hope to find out his missing son. An infertile woman cherishes the hope of being a mother even in her old age. Humans try to hope even in serious situations. I can give up all these hopes. So my body becomes so thin.”

The king Vīradyumna (Viradyumna) could remember the insult of Tanu Muni in past. He was repentant for this action. But he could not prepare his mind to leave the hope of getting his son back, as advised by Tanu Muni. The king bowed down to Tanu Muni’s feet and told him- “I will remember your advice of sacrificing hope. I will try to follow this in future. But please give me back my only son”. Tanu Muni was kind enough to get back the missing son of the king through the power of his meditation. He also scolded the son for his past misdeeds. Then, bereft of any sense of anger or animosity, Tanu Muni went away from Vadrikāśrama.

Here ends the short tale of Maharṣi (Maharshi) Tanu as narrated by Ṛṣabha (Rishabha). The tale of Vīradyumna (Viradyumna) getting back his missing son is only a part of the greater narrative. The thinness of Tanu Muni and his philosophy of life are the essence of this narrative of Ṛṣabha (Rishabha). Basically, ‘Tanu’ means ‘body’. Another meabning of ‘Tanu’ is ‘thin’. ‘Tanukaraṇ’ (Tanukaran) means to diminish, to weaken or, in simple words, to discard. The name of Tanu Muni indicates his physical weakness. But this weakness is used here in a symbolic way. Tanu Muni realized that hope was the reason of all his unhappiness. So he attempted to discard his inherent desire, his earthly attachments, and his hopes and finally he succeeded to sacrifice all these. His indifference and sacrifice were represented through his physical weakness. The commentator, Nīlakaṇtha (Nilakantha) explained the difference between weakness and strength described in this tale-” The person who can overcome hopes or, in other terms, who can discard all the earthly desires from his mind and body, is kṛśa (krisa) or thin. His thinness lies in his indifference towards his earthly desires. On the other hand, the person who is driven by hope, can be called akṛśa (akrisa) or puṣta (pushta) or content, because he cannot give up physical desires. His mind and body are immersed in earthly impulses-
Ya āśājitaḥ sa kṛśaḥ, yena āśā jitā sa puṣta.”

As Tanu Muni had won over hope, he had no anger, no animosity within him. He made king Vīradyumna (Viradyumna) realize his past misdeeds and insults. But being moved by the pain and hopeless condition of king Vīradyumna (Viradyumna), he attempted to help the sad king,Vīradyumna (Viradyumna) to get back his son. Besides this, he also advised the king to live life in an indifferent way, leaving the hopes and desires. It can be noticed that while giving advice, Tanu Muni tried to convince the king that many people come to the king asking help. Someone asks for justice, some for money. They are common men. All of them are not reluctant sages. The king who cares for his subject should try to fulfill their wishes as much as possible. This idea of doing good to the king’s subjects is also linked with the advice to the king to give up hopes. The hope and the subsequent desire can be harmful for the king and his kingdom. Excessive demands for money can make the king torturous towards his subjects. Again, uncontrollable imperialism can bring in disastrous war. So it is duty of the king to overcome desire. For this very idea, Ṛṣabha’s (Rishabha’s) advice is included in the Rājadharmānuśasana (Rajadharmanusasana) Parva of the Śāntiparva (Santiparva).

At the end, Ṛṣabha (Rishabha) told king Sumitra- “Mahārāja (Maharaja), your hope of getting the deer is quite insignificant in comparison with the hope of king Vīradyumna (Viradyumna) of getting his son back. Please give up your desire”. King Sumitra gave up his craving for the deer hunting and calmed down.
After narrating Ṛṣabhagītā (Rishabhagita), Bhīṣma (Bhishma) also advised king Yudhiṣthira (Yudhishthira) to give up hope and to be quiet like a mountain and to live life and to take care of his subjects in a composed way-
Sthiro bhava mahārāja himavāniva parvataḥ.
Besides this, he consoled the repentant Yudhiṣthira (Yudhishthira) who was regretting the killing of his relatives and advised him-
“There was no treaty with Duryodhana. It results into this terrible war. Please don’t be upset thinking about this-
Śrutvā mama mahārāja na santaptumihārhasi.