The Book of Jonah begins with God's call to the famous reluctant prophet:
“Arise, go to Nin′eveh, that great city, and cry against it; for their wickedness has come up before me.”
As far as I can tell the nature of this wickedness is not specified in the text. Are there clues? It does state that the reason Jonah fled was because he did not want Nineveh to receive God's mercy. Was their wickedness that they were Israel's enemy, that they worshiped other gods, that they had made an alliance with northern Israel when God favored Southern Judah? Was it that they were sexual sinners like Sodom, that they oppressed widows and orphans, "all of the above," or what? If there are no good clues in the immediate text, what do other biblical references to the city tell us? What do ancient and modern commentators suggest that would help us know what exactly Nineveh repented for?