John Calvin Reformed @genevareformer

Jonah, by saying that he went to Nineveh according to God’s command, proves in the first place, as I have said, how great was the power and energy of his faith; for though Jonah had considered the greatness and pride of the city, he seems to have forgotten that he was an obscure man, alone, and unarmed; but he had laid hold on weapons capable...

John Gill Reformed Baptist @doctorgill

So Jonah arose, and went unto Nineveh, according to the word of the Lord,.... He was no longer disobedient to the heavenly vision; being taught by the rod, he acts according to the word; he is now made willing to go on the Lord's errand, and do his business, under the influence of his power and grace; he stands not consulting with the flesh, but...

Jamieson-Fausset-Brown Reformed @jfbcommentary

arose and went--like the son who was at first disobedient to the father's command, "Go work in my vineyard," but who afterwards "repented and went" (). Jonah was thus the fittest instrument for proclaiming judgment, and yet hope of mercy on repentance to Nineveh, being himself a living exemplification of both--judgment in his entombment in the fish, mercy on repentance in his deliverance.