'Sackcloth' in the Bible

Woe unto thee, Chorazin! woe unto thee, Bethsaida! for if the mighty works had been done in Tyre and Sidon which were done in you, they would have repented long ago in sackcloth and ashes.

Woe unto thee, Chorazin! woe unto thee, Bethsaida! for if the mighty works had been done in Tyre and Sidon, which were done in you, they would have repented long ago, sitting in sackcloth and ashes.

And I saw when he opened the sixth seal, and there was a great earthquake; and the sun became black as sackcloth of hair, and the whole moon became as blood;

And I will give unto my two witnesses, and they shall prophesy a thousand two hundred and threescore days, clothed in sackcloth.