The evil minded Hiranyakashipu had Prahlaad brain washed by competent instructors for long, because he saw signs of devotion to Thee and also the ridicule of the Asuras in his son. He however rejected all their teachings as leading only to evil and grew up with his devotional zeal.
On being asked about what was the best that he had learned, he answered that devotion to Thee was the greatest. Agitated at this, Hiranyakashipu was very angry with the teachers, but they told him that this was his son's natural inclination. At this he started planning ways to kill Prahlaad who was Thy great devotee, having taken refuge at Thy feet.