Jonah 3:5-6

The people of Nineveh believed and trusted in God; and they proclaimed a fast and put on sackcloth [in penitent mourning], from the greatest even to the least of them. When word reached the king of Nineveh [of Jonah’s message from God], he rose from his throne, took off his robe, covered himself with sackcloth and sat in the dust [in repentance].