And God saw their works, that they turned from their evil way; and God relented of the disaster, that he had said that he would bring upon them; and he did it not.
All Commentaries on Jonah 3:10 Go To Jonah 3
Jerome
AD 420
There was no response to their repentance; rather, God met their questioning with silence. Thus [the outcome of] their repentance is left uncertain, that being doubtful of their salvation, they may repent more vehemently and know the mercy, patience and compassion of God even more.