'Sackcloth' in the Bible

His servants said to him, “Behold now, we have heard that the kings of the house of Israel are merciful kings, please let us put sackcloth on our loins and ropes on our heads, and go out to the king of Israel; perhaps he will save your life.”

So they girded sackcloth on their loins and put ropes on their heads, and came to the king of Israel and said, “Your servant Ben-hadad says, ‘Please let me live.’” And he said, “Is he still alive? He is my brother.”

It came about when Ahab heard these words, that he tore his clothes and put on sackcloth and fasted, and he lay in sackcloth and went about despondently.