Jonah 3:4-6 English Standard Version (ESV)
4 Jonah began to go into the city, going a day's journey. And he called out, “Yet forty days, and Nineveh shall be overthrown!” 5 And the people of Nineveh believed God. They called for a fast and put on sackcloth, from the greatest of them to the least of them.
The People of Nineveh Repent
6 The word reached[a] the king of Nineveh, and he arose from his throne, removed his robe, covered himself with sackcloth, and sat in ashes.