Kṛṣṇa and Balarāma learned the art of cutting valuable stones such as diamonds, and They also learned the art of questioning and answering by immediately composing poetry within the mind. They learned the science of the action and reaction of physical combinations and permutations. They learned the art of a psychiatrist, who can understand the psychic movements of another person. They learned how to satisfy one’s desires. Desires are very difficult to fulfill; but if one desires something which is unreasonable and can never be fulfilled, the desire can be subdued and satisfied, and that is an art. By this art one can also subdue sex impulses when they are aroused, as they are even in brahmacārī life. By this art one can make even an enemy one’s friend or transfer the direct action of a physical element to other things.
Lord Kṛṣṇa and Balarāma, the reservoir of all knowledge, exhibited Their perfect understanding of all the arts and sciences mentioned above. Then They offered to serve Their teacher by awarding him anything he desired. This offering by the student to the teacher or spiritual master is called guru-dakṣiṇā. It is essential that a student satisfy the teacher in return for any learning received, either material or spiritual. When Kṛṣṇa and Balarāma offered Their service in this way, the teacher, Sāndīpani Muni, thought it wise to ask Them for something extraordinary, something no common student could offer. He therefore consulted with his wife about what to ask from Them. He and his wife had already seen the extraordinary potencies of Kṛṣṇa and Balarāma and could understand that the two boys were the Supreme Personality of Godhead. They decided to ask for the return of their son, who had drowned in the ocean near the shore at Prabhāsa-kṣetra.
When Kṛṣṇa and Balarāma heard from Their teacher about the death of his son, They immediately started for Prabhāsa-kṣetra on Their chariot. Reaching the beach, They asked the controlling deity of the ocean to return the son of Their teacher. The ocean deity immediately appeared before the Lord and offered Him all respectful obeisances with great humility.
The Lord said, “Some time back you caused the drowning of the son of Our teacher. I order you to return him.”
The ocean deity replied, “The boy was not actually taken by me but was captured by a demon named Pañcajana. This great demon generally remains deep in the water in the shape of a conchshell. The son of Your teacher might be within the belly of the demon, having been devoured by him.”
On hearing this, Kṛṣṇa dove deep into the water and caught hold of the demon Pañcajana. He killed him on the spot but could not find the son of His teacher within his belly. Therefore He took the demon’s dead body (in the shape of a conchshell) and returned to His chariot on the beach of Prabhāsa-kṣetra.
From there He started for Saṁyamanī, the residence of Yamarāja, the superintendent of death. Accompanied by His elder brother, Balarāma, who is also known as Halāyudha, Kṛṣṇa arrived there and blew on His conchshell. Hearing the vibration, Yamarāja appeared and received Śrī Kṛṣṇa with all respectful obeisances. Yamarāja could understand who Kṛṣṇa and Balarāma were, and therefore he immediately offered his humble service to the Lord. Kṛṣṇa had appeared on the surface of the earth like an ordinary human being, but actually Kṛṣṇa and Balarāma are the Supersoul living within the heart of every living entity. They are Viṣṇu Himself but were playing just like ordinary human boys. When Yamarāja offered his services to the Lord, Śrī Kṛṣṇa asked him to return His teacher’s son, who had come to him as a result of his work. “Considering My ruling supreme,” said Kṛṣṇa, “you should immediately return the son of My teacher.”