According to the Book of Jonah (Hebrew Bible / Old Testament), the people of Nineveh faced a death sentence—then didn't.
Jonah, a reluctant prophet, finally enters Nineveh (described as "an exceedingly great city, three days' journey across") and announces: "Forty more days and Nineveh will be overthrown" (Jonah 3:4).
Remarkably, the city believes him. King to commoner—fasting, sackcloth, ashes. The king decrees: "Let neither man nor beast, herd nor flock, taste anything... let everyone call urgently on God. Let them give up their evil ways and their violence. Who knows? God may yet relent" (Jonah 3:7–9).
God relents. "When God saw what they did and how they turned from their evil ways, he relented and did not bring on them the destruction he had threatened" (Jonah 3:10).
The story isn't about Assyrian history. It's about divine mercy exceeding human categories—even for "the bloody city" (Nahum 3:1). Nineveh's fictional reprieve becomes a mirror: if they can repent, who can't?
No biblical punishment befell Nineveh in Jonah. The destruction came later (612 BCE)—by Median-Babylonian armies, not divine fire.