'Dust on Their Heads' in the Bible

Unhappy are you, Chorazin! Unhappy are you, Beth-saida! For if the works of power which were done in you had been done in Tyre and Sidon, they would have been turned from their sins in days gone by, clothing themselves in haircloth and putting dust on their heads.

And they cast dust on their heads, and cried, weeping and wailing, saying, Alas, alas, that great city, wherein were made rich all that had ships in the sea by reason of her costliness! for in one hour is she made desolate.