But when he moves about in sleep (and dream), then these are his worlds. He is, as it were, a great king; he is, as it were, a great Brahmana; he rises, as it were, and he falls. And as a great king might keep in his own subjects, and move about, according to his pleasure, within his own domain, thus does that person (who is endowed with intelligence) keep in the various senses (pranas) and move about, according to his pleasure, within his own body (while dreaming).

In plain words: Agatasatru explains that when a person dreams, the dream becomes his world. In it he may seem to be a great king or a great priest, or seem to rise and fall. Like a king moving freely around his own kingdom, the self takes the senses with it and moves as it likes within its own body.