The phrase "a lying tongue" represents a person who tells lies. Crushing people represents causing them trouble. Alternate translation: "A liar hates those he hurts by his lies" (See: [[rc://en/ta/man/jit/figs-synecdoche]] and [[rc://en/ta/man/jit/figs-metaphor]])
The phrase "a flattering mouth" represents a person who flatters people. Possible meanings are 1) a person who flatters others causes trouble or 2) a person who flatters others ruins them (See: [[rc://en/ta/man/jit/figs-synecdoche]])