This rhetorical question emphasizes that people who have the Lord's protection should not be afraid of human beings. This can be written as a statement. AT: "Do not be afraid of men ... like grass." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This phrase compares men to grass to emphasize that their lives are short and that they die quickly. AT: "who live and die quickly like grass" or "who will wither and disappear like grass" (See: [[rc://en/ta/man/translate/figs-simile]])