Here "a bitter thing" represents actions that harm people, and "turn justice into a bitter thing" represents harming people rather than doing for them what is just. Alternate translation: "say that they are doing what is just, but instead they harm people" or "refuse to do what is just and harm people instead" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This represents treating righteousness as if it were worthless. Alternate translation: "treat righteousness as though it were as unimportant as dirt" or "you despise what is righteous" (See: [[rc://en/ta/man/translate/figs-metaphor]])