'Sackcloth' in the Bible

His servants said to him, “Consider this: we have heard that the kings of the house of Israel are merciful kings. So let’s put sackcloth around our waists and ropes around our heads, and let’s go out to the king of Israel. Perhaps he will spare your life.”

So they dressed with sackcloth around their waists and ropes around their heads, went to the king of Israel, and said, “Your servant Ben-hadad says, ‘Please spare my life.’”So he said, “Is he still alive? He is my brother.”

When Ahab heard these words, he tore his clothes, put sackcloth over his body, and fasted. He lay down in sackcloth and walked around subdued.