'Sackcloth' in the Bible

And it cometh to pass, at the king's hearing the words of the woman, that he rendeth his garments, and he is passing by on the wall, and the people see, and lo, the sackcloth is on his flesh within.

And it cometh to pass, at king Hezekiah's hearing, that he rendeth his garments, and covereth himself with sackcloth, and entereth the house of Jehovah,

and sendeth Eliakim, who is over the house, and Shebna the scribe, and the elders of the priests, covering themselves with sackcloth, unto Isaiah the prophet, son of Amoz,