Matthew 12:34-40

You brood of vipers, how can you, being evil, speak what is good? For the mouth speaks out of that which fills the heart. The good man brings out of his good treasure what is good; and the evil man brings out of his evil treasure what is evil. But I tell you that every careless word that people speak, they shall give an accounting for it in the day of judgment. For by your words you will be justified, and by your words you will be condemned.” Then some of the scribes and Pharisees said to Him, “Teacher, we want to see a sign from You.” But He answered and said to them, “An evil and adulterous generation craves for a sign; and yet no sign will be given to it but the sign of Jonah the prophet; for 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.