Here the word "flesh" represents all humans. The idiom to "see" means to understand. Alternate translation: "all people will understand" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-idiom]])
This can be stated in active form. Alternate translation: "it will not go out" or "no one will quench it" (See: [[rc://en/ta/man/jit/figs-activepassive]])