Thou art knowledge and ignorance, thou art truth and untruth; thou art poison and nectar; thou art the performance and continuance of acts and thou art the actions laid down in the Vedas. Thou art the enjoyer of the fruits of all actions and the means for effecting them. Thou, Vishnu, who art all, art the fruit of all acts of piety. Thou art in me, in others and spread all over the vast universe. Thy universal manifestation indicates might and goodness. O lord.

In plain words: Prahlada says Vishnu is both knowledge and ignorance, truth and untruth, poison and nectar. He is every action, the one who receives its results, and the reward of every good deed. He is in Prahlada, in others, and everywhere in the universe.