The Sign of Jonah
…39Jesus replied, “A wicked and adulterous generation demands a sign, but none will be given it except the sign of the prophet Jonah. 40 For as Jonah was three days and three nights in the belly of the great fish, so the Son of Man will be three days and three nights in the heart of the earth.

John 11:9-10, “Are there not twelve hours in the day? If someone should walk in the day, he does not stumble, because he sees the light of this world. But, if someone should walk in the night, he stumbles, because the light is not in him.