Srimad Bhagavatham : 5.4.4.
Due to getting a perfect son according to his desire, King Nabhi was always overwhelmed with transcendental bliss and was very affectionate to his son. It was with ecstasy and a faltering voice that he addressed Him, “My dear son, my darling.” This mentality was brought about by yogamaya, whereby he accepted the Supreme Lord, the supreme father, as his own son. Out of His supreme good will, the Lord became his son and dealt with everyone as if He were an ordinary human being. Thus King Nabhi began to raise his transcendental son with great affection, and he was overwhelmed with transcendental bliss, joy and devotion.
The word maya is used in the sense of illusion. Considering the Supreme Personality of Godhead to be his own son, Maharaja Nabhi was certainly in illusion, but this was transcendental illusion. This illusion is required; otherwise how can one accept the supreme father as his own son? The Supreme Lord appears as the son of one of His devotees, just as Lord Krishna appeared as the son of Yasoda and Nanda Maharaja. These devotees could never think of their son as the Supreme Personality of Godhead, for such appreciation would hamper their relationship of paternal love.