"God’s object lesson:
--He caused a plant to grow to
give shade to Jonah as he sat hoping 
for Nineveh’s destruction to happen
after all.
--Then He caused a worm to gnaw at it so it died.
--When Jonah
was unreasonably angry about the plant withering away, God compared
Jonah’s pity for the plant to His pity for the immeasurably greater loss
Nineveh’s destruction would entail: “more than 120,000 persons who do
not know their right hand from their left, and also much cattle” (Jonah 4:11).
The ending of Jonah feels unresolved: God’s question, “Should I not pity Nineveh?” is unanswered, confronting each of us.
There are many
people today who have yet to hear the Gospel, and as Jonah was commanded
to go, we have also been commanded to carry the Gospel into the whole
world....our compassion
for the unsaved should prompt us to be obedient to the Great Commission." CMI