'Sackcloth' in the Bible

But his servants said to him, “We have heard that the kings of the house (royal line) of Israel are merciful kings. Please let us put sackcloth around our loins and ropes on our necks [as symbols of submission], and go out to the king of Israel; perhaps he will spare your life.”

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

Now when Ahab heard these words [of Elijah], he tore his clothes, put on sackcloth and fasted, and he lay in sackcloth and went about dejectedly (mourning).