Commentators stress that Nineveh's fasting and sackcloth were only outward signs. The true repentance that moved God was their decision to "turn every one from his evil way." As one scholar puts it, the honor of a fast is not abstinence from food, but avoidance of sin. True repentance involves a change of heart that leads to a change in behavior, especially abandoning specific, habitual sins like the "violence" of the Ninevites.