'Sackcloth and Ashes' in the Bible

And in every province, wherever the king's command and his decree came, there was great mourning among the Jews, and fasting, and weeping and wailing. And many lay in sackcloth and ashes.

Is it such a fast that I have chosen? A day for a man to afflict his soul? Is it to bow down his head like a bulrush, and to spread sackcloth and ashes under him? Will you call this a fast and a day pleasing to Jehovah?

Woe to you, Chorazin! Woe to you, Bethsaida! For if the powerful acts which were done in you had been done in Tyre and Sidon, they would have repented long ago in sackcloth and ashes!

Woe to you, Chorazin! Woe to you, Bethsaida! For if the mighty works which have been done in you had been done in Tyre and Sidon, they would have repented a long while ago, sitting in sackcloth and ashes.