'Sackcloth' in the Bible

"How terrible it will be for you, Chorazin! How terrible it will be for you, Bethsaida! Because if the miracles that happened in you had taken place in Tyre and Sidon, they would have repented long ago in sackcloth and ashes.

"How terrible it will be for you, Chorazin! How terrible it will be for you, Bethsaida! If the miracles that happened in you had taken place in Tyre and Sidon, they would have repented long ago, sitting in sackcloth and ashes.

Then I saw the lamb open the sixth seal. There was a powerful earthquake. The sun turned as black as sackcloth made of hair, and the full moon turned as red as blood.

I will give my two witnesses who wear sackcloth the authority to prophesy for 1,260 days."