And if they should say to him: 'If everything that exists is contained in that city of Brahman, all beings and all desires (whatever can be imagined or desired), then what is left of it, when old age reaches it and scatters it, or when it falls to pieces?'

In plain words: Then students might ask: if everything is held inside the body, what is left when old age wears the body down or it falls apart in death?