Salutation unto that Great Spirit, whose incarnate forms on earth the deities adore, being unable to behold his true form. Salutation unto that Great God Vishnu, the witness of all, who being present in all minds, beholds the good and evil of all. Salutation unto that Vishnu, from whom this world is not distinct. May He, who is the object of the world's meditation, its beginning, and who is undecaying, be propitiated with me.

In plain words: Prahlada says even the gods cannot see Vishnu's true form, so they worship his forms on earth. Vishnu lives in every mind and sees all the good and bad people do. Prahlada asks this Vishnu to be pleased with him.