SB 4.12.3
na bhavan avadhid yaksan
na yaksa bhrataram tava
kala eva hi bhutanam
prabhur apyaya-bhavayoh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Actually, you have not killed the Yaksas, nor have they killed your brother, for the ultimate cause of generation and annihilation is the eternal time feature of the Supreme Lord.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the master of the treasury addressed him as sinless, Dhruva Maharaja, considering himself responsible for killing so many Yaksas, might have thought himself otherwise. Kuvera, however, assured him that factually he had not killed any of the Yaksas; therefore, he was not at all sinful. He did his duty as a king, as it is ordered by the laws of nature. “Nor should you think that your brother was killed by the Yaksas,” said Kuvera. “He died or was killed in due course of time by the laws of nature. Eternal time, one of the features of the Lord, is ultimately responsible for annihilation and generation. You are not responsible for such actions.”