Kṛṣṇa Recovers the Son of His Teacher
285
It is customary, after being initiated in the  Gāyatrī mantra , for one to live away from home for some time under the care of the  ācārya  in order to be trained in spiritual life. During this period one has to work under the spiritual master as an ordinary menial servant. There are many rules and regulations for a  brahmacārī  living under the care of an  ācārya , and both Lord Kṛṣṇa and Balarāma strictly followed those regulative principles while living under the instruction of their spiritual master, Sāndīpani Muni, in his place in northern India. According to scriptural injunctions, a spiritual master should be respected and be regarded on an equal level with the Supreme Personality of Godhead. Both Kṛṣṇa and Balarāma exactly followed those principles with great devotion and underwent the regulations of  brahmacarya , and thus They satisfied Their spiritual master, who instructed Them in Vedic knowledge. Being very satisfied, Sāndīpani Muni instructed Them in all the intricacies of Vedic wisdom as well as in supplementary literatures such as the  Upaniṣads . Because Kṛṣṇa and Balarāma happened to be  kṣatriyas , They were specifically trained in military science, politics and mathematics. In politics there are six departments of knowledge—how to make peace, how to fight, how to pacify, how to divide and rule, how to give shelter, etc. All these items were fully explained and instructed to Kṛṣṇa and Balarāma.
The ocean is the source of water in a river. The cloud is created by the evaporation of ocean water, and the same water is distributed as rain all over the surface of the earth and then returns toward the ocean in rivers. So Kṛṣṇa and Balarāma, the Supreme Personality of Godhead, are the source of all kinds of knowledge, but because They were playing like ordinary human boys, They set the example so that everyone would receive knowledge from the right source. Thus They agreed to take knowledge from a spiritual master.
After hearing only once from the teacher, Kṛṣṇa and Balarāma learned all the arts and sciences. In sixty-four days and sixty-four nights They learned all the necessary arts and sciences that are required in human society. During daytime They took lessons on a subject from the teacher, and by nightfall, after having heard from the teacher, They were expert in that department of knowledge.
First of all They learned how to sing, how to compose songs and how to recognize the different tunes; They learned the favorable and unfavorable accents and meters, how to sing different kinds of rhythms and melodies, and how to follow them by beating different kinds of drums. They learned how to dance with rhythm, melody and different songs.