In this episode (Lk 11: 29-32), Luke presents Jesus’ reply to the demand for “a sign from heaven” expressed in verse 16. The Lukan form of the saying is derived from ‘Q’ tradition (Cf. Mt 12: 38-42). Part of these sayings is found in their counterpart in Mark (Mk 8: 11-12), where the Pharisees demand a sign from heaven. At this stage it is worthwhile to compare the four synoptic texts which refer to the demand for a sign and Jesus’ response to it.
Mark 8: 11-12 = Matthew 16: 1-4
Luke 11: 29-32 = Matthew 12: 38-42
[St. Paul writes that such demand for heavenly sign was a feature of the Judaism of his day (Cf. 1 Cor 1: 22a; see also Acts 5: 36)]
In order to understand the meaning of the sayings in this section, especially that of “the sign of Jonah,” it is necessary to have a clear idea of the story of Jonah in the Old Testament. What is important to note in this story is that Jonah had to remain within the belly of the fish for three days and three nights as a punishment for his unwillingness to accept and obey God’s plan to save the Ninevites. God’s punishment and the eventual deliverance of Jonah from the belly of the fish cannot be said to be a sign for the Ninevites. For, as far as the story goes, they are not even told about the ‘miraculous deliverance’ of Jonah. Another point to be noted is that at the preaching of Jonah the Ninevites – from the king to the last animal – responded to God’s call to repentance.
In our episode (Lk 11: 29-32) Jesus refuses to comply with the request of his contemporaries for a sign, that is, something besides and beyond his miracles and exorcisms, or any special manifestation of superhuman powers in proof of his claims. The devil too had such a demand in asking Jesus to throw himself down from the pinnacle of the temple (Lk 4: 9-11). Jesus refuses to make any show of such feats of power. His answer is: “on sign shall be given to (this generation) except the sign of Jonah…”.
In what sense was Jonah a sign to the Ninevites? Is Jesus referring to Jonah’s stay in the belly of the fish?
As stated above, it is hardly meaning in Luke’ gospel. In Matthew’s gospel such a significance is added by the evangelist. We should not read Matthew’s gospel meaning into Luke’s text. The Lukan meaning of the phrase is found in verse 30: “For as Jonah became a sign to the men of Nineveh, so will the Son of man be to this generation”.
Therefore, the sign of Jonah in Luke is both the person of Jonah and his preaching of repentance. Verse 32 confirms this meaning of the sign. To those who wanted a spectacular proof from Jesus to show that he is truly the one sent by God, Jesus’ reply is that just as Jonah was sent by God, Jesus (“something greater than Jonah”) is sent by God. The only sign that will be made available to his contemporaries by God is Jesus’ person and his preaching. Jonah preached repentance and the Ninevites recognized God’s demand of conversion. But Jesus’ contemporaries do not recognize God’s call in Jesus’ person and words. That is why the Ninevites will accuse and condemn this unrepentant generation (Lk 11: 32; Cf. Lk 7: 31-34). Jesus further contrasts the unresponsiveness of this generation with the positive response of another non-Israelite, the queen of the South, that is, of Sheba (Cf. Kgs 10: 1-13; 2 Chr 9: 1-12). She came from South-west Arabia to listen to the wisdom of Solomon. Even though Jesus is “something greater than Solomon” (Lk 11: 31), his Jewish contemporaries refuse to listen to the greatest wisdom, Jesus.