'Haircloth' in the Bible

And the people of Nineveh had belief in God; and a time was fixed for going without food, and they put on haircloth, from the greatest to the least.

And the word came to the king of Nineveh, and he got up from his seat of authority, and took off his robe, and covering himself with haircloth, took his seat in the dust.

And let man and beast be covered with haircloth, and let them make strong prayers to God: and let everyone be turned from his evil way and the violent acts of their hands.