PURPORT

Although Hiranyakasipu was purified as soon as he came in contact with the Lord's lap and the Lord saw him, Prahlada Maharaja still wanted to hear from the Lord's own mouth that his father had been purified by the Lord's causeless mercy. Prahlada Maharaja offered this prayer to the Lord for the sake of his father. As a Vaisnava son, despite all the inconveniences imposed upon him by his father, he could not forget his father's affection.