Shouldn't I be concerned for Nineveh, that great city, in which are more than one hundred twenty thousand persons who can't discern between their right hand and their left hand; and also much cattle?"
V. Both Jonah and Jesus, through their delivery from death, were "signs" to the Gentiles.  Jesus declared that "Jonah became a sign to the Ninevites" (Luke 11:30), adding that, "So shall also the Son of man be to this generation."  The implication of this is that Jonah's delivery from death was the "word that came unto the king," leading to the conversion of Nineveh.  The reason that Jonah's message was received in Nineveh and produced such remarkable results was that this "sign" of Jonah convinced them absolutely that God had indeed sent him.  In a similar manner, the resurrection of Christ is the great wonder that declared Jesus to be "the Son of God with power"  (Romans 1:4), leading to the conversion of millions all over the world.