nabhis tu yathabhilasitam suprajastvam avarudhyati-pramoda-bhara-vihvalo gadgadaksaraya gira svairam grhita-naraloka-sadharmam bhagavantam purana-purusam maya-vilasita-matir vatsa tateti sanuragam upalalayan param nirvrtim upagatah.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
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 yoga-maya, 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.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
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 Krsna 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 parental love.