At an advanced age one generally cannot beget a male child. If by chance one does beget a child at this age, the child is generally female. Thus Vasudeva indirectly asked Nanda Maharaja whether he had actually begotten a male child or a female child. Vasudeva knew that Yasoda had given birth to a female child, whom he had stolen and replaced with a male child. This was a great mystery, and Vasudeva wanted to determine whether this mystery was already known to Nanda Maharaja. On inquiring, however, he was confident that the mystery of Krsnas birth and His being placed in the care of Yasoda was still hidden. There was no danger, since Kamsa at least could not learn what had already happened.