'Sackcloth' in the Bible

His servants said to him, "See now, we have heard that the kings of the house of Israel are merciful kings. Please let us put sackcloth on our bodies, and ropes on our heads, and go out to the king of Israel. Maybe he will save your life."

So they put sackcloth on their bodies and ropes on their heads, and came to the king of Israel, and said, "Your servant Ben Hadad says, 'Please let me live.'" He said, "Is he still alive? He is my brother."

It happened, when Ahab heard those words, that he tore his clothes, and put sackcloth on his flesh, and fasted, and lay in sackcloth, and went softly.