Prahlāda said,—"That Vishnu is not only present in my mind, but he pervades the whole universe; He is omnipresent and commands me, thyself and all creatures". Hiranyakashipu said,—"Away with this wicked boy; take him again to the preceptor's house and govern him; perhaps he has been taught by some vicious-minded (men) to sing the glories of my foes".
In plain words: Prahlada says Vishnu is not only in his mind but fills the whole universe and guides everyone, even his father. The king orders the boy taken back to his teacher to be controlled. He thinks someone wicked must have taught him to praise his enemies.