Dora Bas Rivka Silver O'H
Out of his Gourd
Jonah was grieved that the Assyrians responded so readily to G-d's warning, because the Jews were typically obstinate when it came to such things. (Also, the people of Nineveh gave up robbery and other unjust interpersonal behavior, but they still worshipped idols. G-d forgave them nonetheless, and even used them as His instrument to punish Israel, which seemed unfair to Jonah.) Jonah was so despondent that he prayed to G-d that he should die, rather than see the evil that would befall the Jews for not repenting. G-d said, "My, you are upset, aren't you? Come here, I want to show you something."
Jonah left the city and lived in a hut to see what would happen in the city. G-d made a plant called a kikayon grow and shelter Jonah from the hot sun. (The kikayon was possibly a gourd, but there are other translations.) Jonah rejoiced over the kikayon. Then, G-d had a worm eat into the kikayon, which withered, allowing the hot sun to beat down on Jonah. Again, Jonah said that he preferred to die.
G-d replied to Jonah, "You're so upset about a gourd that you didn't even grow yourself! You got it for nothing and it went away just as easily! Shouldn't I give at least as much consideration to a great city of people and animals?" As far as their continuing idolatry, G-d said that the people were childlike, not knowing their right from their left; since they couldn't tell the difference between the real G-d and false "gods," He was not going to punish them for that.
The Book of Jonah is read in its entirety on Yom Kippur afternoon.