Here the author speaks of everything being as temporary as if it were a breath of air. The author uses this rhetorical question to emphasize that everything is temporary. This question can be written as a statement. Alternate translation: "Everything is just a breath." or "Everything is as temporary as a breath." (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-rquestion]])