The word of Yahweh came to Jonah the second time, saying,
"Arise, go to Nineveh, that great city, and preach to it the message that I give you."
So Jonah arose, and went to Nineveh, according to the word of Yahweh. Now Nineveh was an exceedingly great city, three days' journey across.
Jonah began to enter into the city a day's journey, and he cried out, and said, "Yet forty days, and Nineveh shall be overthrown!"
The people of Nineveh believed God; and they proclaimed a fast, and put on sackcloth, from the greatest of them even to the least of them.
The news reached the king of Nineveh, and he arose from his throne, and took off his royal robe, covered himself with sackcloth, and sat in ashes.
He made a proclamation and published through Nineveh by the decree of the king and his nobles, saying, "Let neither man nor animal, herd nor flock, taste anything; let them not feed, nor drink water;
but let them be covered with sackcloth, both man and animal, and let them cry mightily to God. Yes, let them turn everyone from his evil way, and from the violence that is in his hands.
Who knows whether God will not turn and repent, and turn away from his fierce anger, so that we might not perish?"
God saw their works, that they turned from their evil way. God repented of the evil which he said he would do to them, and he didn't do it.