As the crowd pressed in on Jesus, he said, “This evil generation keeps asking me to show them a miraculous sign. But the only sign I will give them is the sign of Jonah. What happened to him was a sign to the people of Nineveh that God had sent him. What happens to the Son of Man will be a sign to these people that he was sent by God.

Luke 11:29-30

For as Jonah was in the belly of the great fish for three days and three nights, so will the Son of Man be in the heart of the earth for three days and three nights.
Matthew 12:40

• Jesus is confronted by a demanding crowd seeking a miraculous sign to prove His authority. They are looking for sensational evidence—a spectacle.
• Jesus responds by refusing their demand for a custom sign, stating that only one will be given: the sign of Jonah.
• This is a powerful, two-part sign: it's about the unique event that validates Jesus' identity, and the compelling message that should lead to repentance.

• Jesus says, "This is an evil and adulterous generation. It demands a sign, but the only sign will be the sign of Jonah." He calls them "evil and adulterous" because their unfaithfulness to God makes them unwilling to accept the authority already demonstrated by His teachings and miracles.
• The Jonah-Christ Parallel (Matthew 12:40): While Luke is concise, the parallel account in Matthew explicitly clarifies the meaning: "For as Jonah was three days and three nights in the belly of a great fish, so will the Son of Man be three days and three nights in the heart of the earth."
  
  • Jonah's "Death" and Rebirth: Jonah's experience in the great fish was a figurative death and resurrection—a miraculous survival that prepared him for his mission.
  • Jesus' Actual Death and Resurrection: Jesus' time "in the heart of the earth" is His burial, followed by His resurrection on the third day. This is the ultimate, undeniable proof of His divine power and His victory over death.
• Unlike the Pharisees' demands for a temporary spectacle, the Resurrection is an eternal, historical fact that validates Jesus' claim to be the Son of God. It is the ultimate proof that His words and works were divine.
• The second part of the sign shifts from the messenger (Jesus' fate) to the message and the response it demands. This is where the comparison to the repentance of Nineveh comes into play.

• Jonah finally preached a message of impending judgment and a call to repentance to the pagan city of Nineveh. The sign was Jonah himself—a man delivered from the belly of a fish after three days—whose bizarre survival validated his message.
• Jesus points to their successful conversion: "The people of Nineveh will stand up against this generation on judgment day and condemn it, for they repented at the preaching of Jonah..."
  
  • The people of Nineveh, who were Gentiles, repented immediately when confronted by a prophet whose credentials were his miraculous deliverance.
• The Greater Authority: Jesus continues: "...and now, someone greater than Jonah is here."
  
  • Jesus is saying: "You have someone greater than a delivered prophet—you have the Son of Man, validated by mighty miracles, who will soon rise from the dead. Yet, you refuse to repent and believe."
  • The judgment is intensified because they reject God Incarnate after seeing His signs, while the Ninevites repented before a mere man.

• The Inescapable Sign: The core message of Luke 11 is that every generation is given the sign of Jonah—the Resurrection of Christ—as the final evidence of His divine authority.
• Jesus warns that those who heard His preaching were judged by the repentance of others who had less information. We, who have the full testimony of the Gospel and the Bible, face an even greater responsibility.
• Jesus validated His message through His resurrection so that we would recognize His authority, repent of our sins, and follow Him.

The sign of Jonah is Jesus' final, definitive proof of who He is. It compels us to ask the same question the people of Nineveh faced: Do we submit to the authority of the one who conquered the grave, or do we stand condemned by our refusal to repent in the face of absolute truth?