30 because just as Jonah became a sign to the people of Nineveh, so the Son of Man will be a sign to this generation.
Luke 11:30 Cross References - ISV
Jonah 1:17
17 Now the LORD had prepared a large sea creature to swallow Jonah, and Jonah was inside the sea creature for three days and three nights.
Jonah 2:10
10 Then the LORD spoke to the sea creature, and it spewed Jonah onto the dry land.
Jonah 3:2-10
2 “Get up and go to Nineveh, that great city, and proclaim to it the message that I tell you.”
3 So Jonah got up and went to Nineveh to do what the LORD had ordered.
Now Nineveh was a very large city, requiring a three-day journey to cross through it. 4 As Jonah started into the city on the first day’s journey, he proclaimed the message, “40 days more and Nineveh will be overthrown!”
5The City of Nineveh RepentsThe people of Nineveh believed God. They called for a fast and put on sackcloth, from the greatest of them to the least important.
6 When the message reached the king of Nineveh, he got up from his throne, removed his royal garments, covered himself with sackcloth, and sat down in ashes.
7 Then he had this proclamation published throughout Nineveh: “By decree of the king and his nobles: No man or animal, herd or flock, is to taste anything, graze, or drink water.
8 Instead, let both man and animal clothe themselves with sackcloth and cry out to God forcefully. Let every person turn from his evil ways and from his tendency to do violence.
9 Who knows but that God may relent, have compassion, and turn from his fierce anger, so that we are not exterminated?”
10 God took note of what they did—that they turned from their evil ways. Because God relented concerning the trouble about which he had warned them, he did not carry it out.
Now Nineveh was a very large city, requiring a three-day journey to cross through it. 4 As Jonah started into the city on the first day’s journey, he proclaimed the message, “40 days more and Nineveh will be overthrown!”
5
10 God took note of what they did—that they turned from their evil ways. Because God relented concerning the trouble about which he had warned them, he did not carry it out.
Matthew 12:40-42
40 because just as Jonah was in the stomach of the sea creature for three days and three nights, so the Son of Man will be in the heart of the earth for three days and three nights.
41 The men of Nineveh will stand up at the judgment and condemn the people living today, because they repented at the preaching of Jonah. But look—something greater than Jonah is here!
42 The queen of the south will stand up and condemn the people living today, because she came from so far away to hear the wisdom of Solomon. But look! Something greater than Solomon is here!”