Here the soldiers are referred to by their face to emphasize how they would have hid their faces because of their shame" AT: "You have caused all your soldiers to hide their faces in shame today" or "You have caused all of your soldiers to be ashamed today" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
This phrase is an exaggeration, but it expresses the very low value that David showed for the army. AT: "are worth very little to you" (See: [[rc://en/ta/man/translate/figs-hyperbole]])