Aruni (pronounced Aaruni) was the son of Arun Rishi and a disciple of Dhaumya Rishi. When he approached his guru to attain knowledge, the guru stipulated certain conditions for his eligibility. This was the tradition of the Upanishads. Generally, the following conditions were to be observed by a pupil:

1. To serve (seva) in the guru’s ashram.

2. To live in the guru’s ashram, away from one’s family.

3. To convince the guru that he, the disciple, would not misuse the knowledge imparted by the guru.

4. To bear all physical hardships during studentship. 

5. To observe brahmacharya.

When Aruni went to study at Dhaumya Rishi’s ashram, the rishi instructed him to look after the ashram’s agricultural land and specifically told him to make small mud walls on its borders to prevent water draining out of the fields. When Aruni arrived at one field, it was raining heavily.

To retain water in the field Aruni began shovelling mud to make a small wall. But the force of the rainwater would break it down. After many failed attempts, an idea occurred to him. He lay down sideways in the breach of the wall. This effectively stopped water spilling out. However, now that the wall was safe because of his body, how could he get up to return to the ashram?

Day turned to night. When Aruni had still not returned, the guru began to worry. He questioned the other disciples. They reminded him about his instructions to Aruni about making the mud walls. Thus, the rishi went off to the fields. Here he called out Aruni’s name. Aruni called back repeatedly to guide the guru to him.

By this time the mud wall behind Aruni had hardened and it was safe for him to get up. Therefore he got up and bowed to the guru. He related the events that prevented him from returning to the ashram. Then, he said, “Now, what is your command?” Despite such an ordeal, Aruni requested for further service. Pleased by Aruni’s enthusiasm to obey his commands, the guru blessed him and taught him para (spiritual) and apara (worldly) vidya. He then told Aruni, “Since you have made the wall [in the field], you will henceforth also be known as Udalak.” Enlightened with knowledge, Aruni-Udalak returned home.

Upamanyu was another disciple of Dhaumya Rishi. When he approached the rishi for knowledge, the latter replied, “Gāhā rakshasva” – “Protect the cows.”

Therefore Upamanyu spent the whole day in the jungle with the cows. When he returned to the ashram in the evening, he used to bow and prostrate to the guru. Once, the guru remarked, “O Upamanyu! You have become chubby. So tell me what do you eat in the jungle?”

Upamanyu replied, “I live by begging alms.”

Guru said, “It is a sin to eat without offering them to the guru. From now on, bring the alms to me. You shall have food only when I give it to you.”

Upamanyu agreed readily, wishing to please the guru. A few days later the guru asked him the same question.

Upamanyu revealed, “After offering alms to the guru, I beg alms again for myself.”

Guru said, “This karma is against dharma. It puts an extra burden on householders. It also becomes a problem for others begging alms. So stop this habit.”

Again, Upamanyu complied by the guru’s wish. A few days later, the guru questioned him.

Upamanyu said, “I drink cow’s milk.”

Guru said, “Again, this is another bad karma. It is improper for you to drink the milk without my permission.”

When the guru asked him again, Upamanyu replied, “I live on the froth that is produced while the calves suckle milk from their mothers.”

Guru said, “Then the calves will remain a little hungry. So, do not take this froth either.”

Upamanyu obeyed this wish of his guru, too. Once, when he became very hungry, Upamanyu forgot all his promises and ate a few ankado leaves [this is a poisonous plant]. This made him blind. While the cows returned to the ashram in the evening, he followed them by listening to their bellowing. On the way, he fell into a well.

Meanwhile, the cows reached the ashram. When the guru noted Upamanyu’s absence, he wondered whether he might have fled, overcome by hunger because of his strict discipline. He then summoned the other pupils to search for Upamanyu. They called out his name every now and then. Soon they heard a reply.

Upamanyu shouted, “O gurudeva! I am here, in a well.”

The pupils pulled him out. Upamanyu then related his story. The guru replied, “Sing the mantras of the Rig Veda in their proper musical metre and pray to the Ashwini Kumars [the twin physicians of the devas]. They will restore your sight.”

Upamanyu obeyed and sang the mantras. The Ashwini Kumars appeared and offered him a malpudo (sweet roti fried in ghee).

Upamanyu replied, “I cannot have this without offering it to my guru.”

The devas tested his firm resolution further, “Once your guru had prayed to us and he ate the malpudo without offering to his guru. So do not worry. Go ahead and eat it.”

Upamanyu remained steadfast and refused. This pleased the devas, “We are pleased with your devotion to your guru. You will regain your sight. You will attain greater fame.”

Upamanyu then related the incident to the guru, who was pleased. He blessed Upamanyu, “You will regain your sight. You will gain knowledge of all the dharma shastras. As you read and study, you will gain greater insight and intuition.”

To please his guru, Upamanyu tolerated hunger and ate only what he was allowed. He obeyed him sincerely without caring for his body, even to the extent that he turned blind. Thus, he attained the guru’s blessings and knowledge.