After his wrongdoing, he showed true repentance by wearing sackcloth and ashes.
She dressed in sackcloth and ashes to express her deep mourning for her loss.
As a form of penance, he wore sackcloth and ashes for a week.
His act of wearing sackcloth and ashes showed his deep remorse for his actions.
In an attempt at atonement, he donned sackcloth and ashes as a sign of his regret.