John Calvin on Jonah 4:1

Jerome commends this grief of Jonah, and compares it to the holy zeal of Paul when he wished himself to be an anathema for his brethren, (Romans 9:3:) for he denies that he grieved because God had showed mercy to so illustrious a city; but because the conversion of the Gentiles was a certain presage of the destruction of the chosen people. As then Jonah perceived as in a mirror the near ruin of Israel, he on this account grieved, if we believe Jerome: but this notion is extremely frivolous; for, immediately after, God reproved Jonah. What then will the foolish and puerile apology of Jerome avail the Prophet, since God has declared that he acted perversely in grieving? Nay, the dullness of Jerome is thus become evident; (thus indeed do I speak of a man, who, though learned and laborious, has yet deprived himself of that praise, which otherwise he might have justly earned.) His wayward disposition everywhere betrayed itself; and he is evidently disproved in this very context, where Jonah shows clearly that the cause of his grief was another, even this, — that he was unwilling to be deemed a false or a lying prophet: hence was his great grief and his bitterness. And this we see, had God not expressed his mind, was unjust and inconsistent with every reason.

We may then conclude that Jonah was influenced by false zeal when he could not with resignation bear that the city of Nineveh should have been delivered from destruction: and he also himself amplifies the greatness of his sin. He might have said, in one word, that it displeased Jonah; but not satisfied with this simple form, he adds, that he felt great displeasure or grief; and he afterwards adds, that he was very angry. Though the beginning may not have been wrong, yet excess was sinful. But he confesses that there was excess, and want of moderation in his grief: since then he accuses himself in plain words what good is it, by false and invented pretenses, to cover what we clearly see cannot be excused? But that it may be more evident why the deliverance of the city of Nineveh displeased Jonah, let us go on with the context —

Jonah 4:2

2. And he prayed unto the Lord, and said, I pray thee, O Lord, was not this my saying, when I was yet in my country? Therefore I fled before unto Tarshish: for I knew that thou art a gracious God, and merciful, slow to anger, and of great kindness, and repentest thee of the evil.

2. Et oravit ad Jehovam et dixit, Obsecro Jehova, an non hic sermo meus, quum adhuc essem in terra mea? Propterea festinavi fugere in Tharsis, quia noveram quod tu sis Deus propitius (vel, plenus gratiae,) et misericors, tardus ad iram, multus clementia, et qui poenitentia duceris super malo.