# whose life-breath is in his nostrils

This describes how man is human and weak by emphasizing that he needs to breath to live. AT: "who is weak and will die" or "who needs the breath in his nose to live" (See: [[rc://en/ta/man/translate/figs-explicit]])

# nostrils

the holes in the nose through which people breathe

# for what does he amount to?

Isaiah uses a question to remind the people of something they should already know. This question can be translated as a statement. AT: "for man amounts to nothing!" or "for man is not worth anything!" (See: [[rc://en/ta/man/translate/figs-rquestion]])