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.
On what basis did they repent? Jonah didn't say, "Repent or destruction comes." He didn't preach repentance at all. In fact, he didn't want them to repent. He became angry when they did repent. One of the only preachers in history who was hoping that he would not have a successful ministry. But they repented on the slim basis of,