Kardama Muni was ordered by his father, Prajapati, to produce children. In the beginning of creation the Prajapatis were meant to produce the large population which was to reside in the planets of the gigantic universe. But Kardama Muni said that although his father was Prajapati, who desired him to produce children, actually his origin was the Supreme Personality of Godhead, Visnu, because Visnu is the origin of everything; He is the actual creator of this universe, He is the actual maintainer, and when everything is annihilated, it rests in Him only. That is the conclusion of Srimad-Bhagavatam. For creation, maintenance and annihilation there are the three deities Brahma, Visnu and Mahesvara (Siva), but Brahma and Mahesvara are qualitative expansions of Visnu. Visnu is the central figure. Visnu, therefore, takes charge of maintenance. No one can maintain the whole creation but He. There are innumerable entities, and they have innumerable demands; no one but Visnu can fulfill the innumerable demands of all the innumerable living entities. Brahma is ordered to create, and Siva is ordered to annihilate. The middle function, maintenance, is taken charge of by Visnu. Kardama Muni knew very well, by his power in progressive spiritual life, that Visnu, the Personality of Godhead, was his worshipable Deity. Whatever Visnu desired was his duty, and nothing else. He was not prepared to beget a number of children. He would beget only one child, who would help the mission of Visnu. As stated in Bhagavad-gita, whenever there is a discrepancy in the discharge of religious principles, the Lord descends on the surface of the earth to protect religious principles and to annihilate the miscreants.