Kṛṣṇa cites His own life as an example. He says that in all the three worlds, there is nothing He is required to do. As the Supreme Lord, He has no unfulfilled desires and nothing to gain from any activity. He is completely full and satisfied in Himself. Yet, He is constantly engaged in work. During His appearance on earth, Kṛṣṇa acted as a prince, a student, a diplomat, and now a charioteer. He followed the rules of society and the duties of His position with total care. He worked even though He didn’t have to. This reveals the altruistic nature of the Divine. Kṛṣṇa works not for Himself, but for the benefit of all living beings. He is showing Arjuna that if God Himself takes the trouble to perform duties for the sake of the world, then a human being should certainly do the same. Service is the highest expression of life, even at the highest level.