Nārada Muni wanted to impress upon people in general that Kṛṣṇa is fully independent. His activities, such as His appearance in the family of Yadu or His friendship with Arjuna, do not necessarily oblige Him to act to enjoy their results. They are all pastimes, and for Him they are all play. But for us they are actual, tangible facts.
After He had killed the Keśī demon, Kṛṣṇa returned to tending the cows with His friends in the forest as though nothing had happened. Thus Kṛṣṇa is eternally engaged in His transcendental activities in Vṛndāvana with His friends, the cowherd boys and gopīs, but sometimes He exhibits the extraordinary prowess of the Supreme Personality of Godhead by killing different types of demons.
Later that morning, Kṛṣṇa went to play with His cowherd boyfriends on the top of the Govardhana Hill. They were imitating the play of thieves and police. Some of the boys became police constables, and some became thieves, and some took the role of lambs. While they were thus enjoying their childhood pastimes, a demon known by the name of Vyomāsura, "the demon who flies in the sky," appeared on the scene. He was the son of another great demon, named Maya. These demons can perform wonderful magic. Vyomāsura took the part of a cowherd boy playing as a thief and stole many boys who were playing the parts of lambs. One after another he took away almost all the boys and put them in the caves of the mountain and sealed the mouths of the caves with stones. Kṛṣṇa could understand the trick the demon was playing; therefore He caught hold of him exactly as a lion catches hold of a lamb. The demon tried to expand himself like a hill to escape arrest, but Kṛṣṇa did not allow him to get out of His clutches. He was immediately thrown to the ground with great force and killed, just as an animal is killed in the slaughterhouse. After killing the Vyoma demon, Lord Kṛṣṇa released all His friends from the caves of the mountain. He was then praised by His friends and by the demigods for these wonderful acts. He again returned to Vṛndāvana with His cows and friends.