Here the word "heart" represents the mind and thoughts. Alternate translation: "The mind of the discerning person" or "The discerning person" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-synecdoche]])
Here the word "mouth" represents the person. The writer speaks of fools desiring foolish things as if they ate foolish things. Alternate translation: "foolish people desire folly as if it were the food that they eat" (See: [[rc://en/ta/man/jit/figs-synecdoche]] and [[rc://en/ta/man/jit/figs-metaphor]])