But it displeased Jonah exceedingly, and he was angry.
Both of these viewpoints, of course, are plausible; but we believe there is a clue in the text itself, in the very next verse (Jonah 4:2). Jonah had observed the wholesale conversion of the people; and his knowledge of God's true nature, mentioned by Jonah in the next verse, led him to the conclusion that God would in no wise destroy a penitent and pleading people.  That Jonah acted upon this deduction would explain the element of uncertainty in the clause, "to see what would become of the city" (Jonah 4:5).  At any rate, the question is one of interest, but not one of importance.