PURPORT

When Vasudeva understood from Nanda Maharaja that the mystery of Krsna's birth and His having been exchanged with Yasoda's daughter was yet undisclosed, he was happy that things were going on nicely. By saying that Vasudeva's daughter, his youngest child, had gone to the heavenly planets, Nanda Maharaja indicated that he did not know that this daughter was born of Yasoda and that Vasudeva had exchanged her with Krsna. Thus the doubts of Vasudeva were dispelled.