Matthew 12:39-41

39But He replied and said to them, “An evil and adulterous generation [that is morally unfaithful to God] craves and demands a [miraculous] sign; but no sign will be given to it except the sign of the prophet Jonah;

40for just as Jonah was three days and three nights in the belly of the sea monster, so will the Son of Man be three days and three nights in the heart of the earth.

41The men of Nineveh will stand up [as witnesses] at the judgment against this generation, and will condemn it because they repented at the preaching of Jonah; and now, something greater than Jonah is here.